History Characters / Ben10

The large character list across four different series has caused this to be split into different pages.

* Characters/Ben10SupportingCharacters

The large character list across three (soon to be four) different series has caused this to be split into different pages.

[[foldercontrol]]

[[folder:Main Characters]]

!Benjamin Kirby Tennyson (Ben 10)
-> Voiced by TaraStrong (as a kid), YuriLowenthal (as a teenager)

* AscendedFanboy
* BerserkButton: Trying to hurt any innocent people or anyone close to him. Then he will get serious and beat the crap out of you. And [[BewareTheNiceOnes God]] [[LetsGetDangerous help]] [[UnstoppableRage you]] if you actually ''suceeded'' in harming someone seriously...
* BewareTheNiceOnes: even though he acts sometimes a bit egocentric and immature, Ben is still a nice, kind-hearted a deeply altruistic guy. But push his BerserkButton, and you ''will'' regret it.
* BookDumb
* TheChosenOne: By the Omnitrix
** TheUnchosenOne: By Azmuth [[spoiler:until the finale of ''Ultimate Alien'', where he finally admits Ben is worthy and gives him the final version of the Omnitrix.]]
* ChronicHeroSyndrome: one of his most defining traits from the beginning of the show; even before he got the Omnitrix, Ben had an almost obssessive desire to help people around him and act like a hero. This is actually a major reason why he JumpedAtTheCall when he got the Omnitrix.
* ComboPlatterPowers
* ComesGreatResponsibility: played with; as noted above, he has a strong will to help people around him and will never use his powers for genuinely malicious purposes, but he is still not above using them for petty reasons as well, especially in the original series.
* FunnySchizophrenia: "Ultimate Sacrifice"
* GenreSavvy
* GreenEyes
* HenshinHero: completed with a green flash and a TransformationSequence for each alien form.
* TheHero
* JerkWithAHeartOfGold: He acts like an immature jerk occasionnally, but deep inside, he has a sincere and strong will to help people.
* JumpedAtTheCall: he even provides the page's quote. Ben ''loves'' possessing the Omnitrix and acting as a hero, both because of the thrill of adventure and because [[ChronicHeroSyndrome it allows him to actually help people]].
* KidHero: Has this role for all three series.
* TheKnightsWhoSaySquee
* LeeroyJenkins: zig-zagged; he tends to act like this sometimes, but other times he will actually display some sense of strategy and cunning, especially in the Alien Force/Ultimate Alien era.
* TheMindIsAPlaythingOfTheBody
* TaughtByExperience
* TransformationNameAnnouncement: in the Alien Force/Ultimate Alien era only. In the original series, he would usually avert this.
* VoluntaryShapeshifting: However, he doesn't have much control over ''which'' form he changes into.

[[AC:Original Series]]
* AesopAmnesia: even lampshaded in ''Destroy All Aliens'':
--->'''Ben''': I have learnt my lesson.
--->'''Gwen''': You will forget it again, but you learnt...
* AntiHero: Type II.
* BrattyHalfPint: a rare heroic example.
* CrouchingMoronHiddenBadass
* DudeWheresMyRespect: His heroics were rarely if ever recognized or acknowledged even by those in on the {{Masquerade}}. [[FamedInStory Later averted]] in the sequels.
* FutureMeScaresMe: Though initially in awe of Ben 10,000, he later calls him on being a JerkAss. Ben 10,000, meanwhile, has a case of IHatePastMe. [[spoiler: Although that isn't the REAL Ben 10,000. Whether Ben would've ended up being that version of Ben 10,000 had he not traveled to the future in the first place is unclear.]]
* HiddenDepths: In ''Ultimate Alien'', it is suggested that the whole IdiotHero act and constant one-liners in this series were [[JerkassFacade a coping mechanism]] so he could deal with having to make life-and-death decisions on a more or less daily basis.
* IdiotHero: often criticized by those around him to be this, though it's kind of justified; after all, he is 10 years old. He does displays creativity on occasions however.
* TheMcCoy
* MouthyKid
* RedOniBlueOni: The red to Gwen's blue.
* [[WhyDidItHaveToBeSnakes Why Did It Have To Be Clowns?]]: Although he did fight it back with Ghostfreak.

[[AC:Alien Force/Ultimate Alien]]
* AcquiredSituationalNarcissism: In ''Ultimate Alien'''s first season finale he cops to this.
* BrilliantButLazy: it's hinted several times Ben is actually much smarter than his attitude would suggest; he has an almost photographic memory and can get a quite correct grade when he is working seriously at school.
* CharacterizationMarchesOn: In ''[[WesternAnimation/Ben10AlienForce Alien Force]]'''s first two seasons, he was a very different character from what he was before; in season 3, the writers took the liberty of making him more like his younger, immature self...[[TookALevelInDumbass a little too much like his younger self]]. Fortunately, by ''Ultimate Alien'' they moderate his competence and silliness as opposed to focusing on one or the other.
* ChickMagnet: He has several girls that like him and doesn't mind that at all, but he doesn't actively pursue women though like a Casanova does. Most notable examples include: Julie Yamamoto, Eunyce, Jennifer Nocturne and Elena Valadis.
* FamedInStory: in the alien underground in ''Alien Force'', then amongst humans as well in ''Ultimate Alien''.
* HeroWithBadPublicity: Though only with most adults. Teens and younger kids (and a few adults) seem to think he's absolutely awesome.
* HeIsAllGrownUp
* HealingHands: With the Omnitrix's genetic-repair function.
* IHatePastMe: "Hate"'s a strong word, but he finds his 10 year old self to be quite annoying.
* TheKirk
* TheMessiah: Less so after ''Alien Force'''s first arc, but still shows some signs.
* MidseasonUpgrade: Ben 10,000 gives Ben all of his locked aliens that he'd used up to that point along with some new ones in the middle of season 2. [[spoiler: He also brought back Swampfire and Waybig after the two were eroded into dust by Eon.]]
* OlderAndWiser: Not ''much'' wiser, mind you. He's still a kid at heart.
** This is subverted when he was at Plumber's Academy. He acts dumb but in the end got a 95 out of 100 because just because he acted dumb, didn't mean he wasn't paying attention.
* {{Pride}}: {{Deconstructed}}. By the first season finale of Ultimate Alien, he outright states that he's grown tired of what comes along with his fame. In fact, his constant pestering due to fame and time it took up was revealed to be a major factor for his [[spoiler: relationship with Julie taking a big hit.]]
* TookALevelInJerkass: In the third season of ''Alien Force'', due to leaving his hero status getting the best of him.

!Gwendolyn "Gwen" Tennyson
-> Voiced by Meagan Smith (as a kid), AshleyJohnson (as a teenager)

* ActionGirl
* TheChick
* EnergyBeing: she has the abilitie to turn into one as part of her Anodite powers, though she rarely does it.
* FieryRedhead
* GreenEyes
* GreenEyedRedhead
* HalfHumanHybrid: 1/4 [[EnergyBeing Anodite]].
* MagicalGirl
* [[TheSmartGuy The Smart Girl]]: even her 10 years old version is ''much'' smarter than the average kid.
* TheSpock

[[AC:Original Series]]
* DistressedDamsel: Often in the first two seasons.
* HairDecorations
* HyperCompetentSidekick: Gwen was a prodigy who could basically instantly master anything, be it athletics, academics, and even the Omnitrix in a "What-If" episode, in which she's instantly better at using it than Ben ever was.
* TheLancer
* LawfulStupid
* LittleMissSnarker: ''especially'' toward Ben.
* TheLoad: In the first season, before becoming the HyperCompetentSidekick.
* PositiveDiscrimination: Often in the last two seasons.
* PowerEchoes
* RedOniBlueOni: The blue to Ben's red.
* {{Tomboy}}: debatable; she dress in relatively tomboyish clothes, but she stills displays interest in shopping.
* TomboyAndGirlyGirl: Tomboy to Kai's Girly Girl in "Benwolf".
* {{Tsundere}}: Type A. She actually does care about Ben, but she seems to be near unable to express her affection for him other than by arguing with him. She even mentionned twice that no one can treat him like trash but her.

[[AC:Alien Force/Ultimate Alien]]
* ADayInTheLimelight: "It's Not Easy Being Gwen" is this, revolving around a day in her life.
* AllGirlsWantBadBoys
* BarrierWarrior
* DrivingTestSmashers
* FullContactMagic
* GlowingEyesOfDoom
* HeroesWantRedheads: [[OfficialCouple Kevin]] certainly does. So does [[HopelessSuitor Cooper]]. And Mike Morningstar doesn't mind [[TermsOfEndangerment complimenting]] her whenever he sees her.
* ImprovisedPlatform
** SteppingStonesInTheSky
* KungFuWizard
* LettingTheirHairDown: In the first two seasons of Ben 10: Alien Force and when wearing a plumber suit.
* MagicSkirt
* {{Mana}}
* MsFanservice: She even appears in bikinis in the [[BeachEpisode beach episodes]].
* OneWingedAngel: Being half Anodite, Gwen is able to transform into a much more powerful Anodite form, but it's apparently very risky as the first time she nearly goes DrunkWithPower.
* [[strike:[[GreenLanternRing Green]]]] [[GreenLanternRing Pink Lantern Ring]]
* ProperTightsWithASkirt
* PureEnergy
* SheIsAllGrownUp
* TeamMom
* TeleportersAndTransporters: She can create one, but with the side effect of having a killer headache afterwards.
* VoiceOfTheLegion: Her Anodite form.
* WhipItGood: A new move she's picked up, as of "Ben 10,000 Returns". She [[IKnowMortalKombat saw it in an old movie]].

!Kevin Ethan Levin (Kevin 11)
-> Voiced by Charlie Schlatter (as a kid), GregCipes (as a teenager)

* DisappearedDad: Devin Levin. KIA, courtesy of Ragnarok.
* EnergyAbsorption: Read the spoilers and you'll understand why he never uses it again after the original series.
* GregCipes: As a teenager.
* HalfHumanHybrid: Half human, half Osmosian.
* HeelFaceRevolvingDoor: Went from neutral to evil shortly before his debut, turned good at the start of ''Alien Force'', [[spoiler: turned evil '''again''' 3/4 through ''Ultimate Alien'''s first season, then reverted back to good in the SeasonFinale.]]
* LongHairedPrettyBoy: His hair reaches his shoulders. By ''Omniverse'', it's a full-blown mullet.
* MissingMom: Until near the end of ''Alien Force''.
* SlasherSmile: Does this a lot as Kevin 11 in ''Ben 10'' [[spoiler: and ''Ultimate Alien''.]]
* [[WickedStepmother Wicked Stepfather]]: Kevin implied to have had one in his youth. [[spoiler: It turns out to be a completely false viewpoint of Kevin when he's insane; his stepfather is actually a good man.]]
* WithGreatPowerComesGreatInsanity: Used in ''Ultimate Alien'' to '''finally''' rectify his extreme change in character. [[spoiler: He falls off the proverbial wagon again five episodes later.]]

[[AC:Original Series]]
* AllYourPowersCombined: He at first had Ben's ability to transform, but after getting frustrated with Ben just giving up on him, he turns into an amalgamation of the original ten aliens.
* ArchEnemy: to Ben, in the original series. He was the second most dangerous, preceded only by Vilgax. Notably, he stayed that way in one of the Ben 10000 alternate futures.
* AxCrazy: As Grandpa Max puts it, "That kid's rowboat is missing a few paddles!"
* ChaoticStupid
* CreepyChild
* EnfantTerrible
* EvilCounterpart: Was basically Ben but without ''any'' of his morals or standards.
* FamilyUnfriendlyDeath: Gives one to Slix Vigma by impaling him with his Diamondhead arm...and if Ben hadn't gone Cannonbolt, he would have been next.
* FreudianExcuse: Everyone treated him like a freak and a monster because of his powers, so the unstable kid basically decided to do his damnedest [[ThenLetMeBeEvil to prove everyone right.]]
** "Nobody's innocent...they just haven't got the chance to make fun of me yet!"
* HumanoidAbomination: Kevin 11,000.
* NotSoDifferent: Part of his introduction.
* TheRival
* TheSociopath: In Ultimate Alien, Max mentioned he was one back then.
* TroublingUnchildlikeBehavior

[[AC:Alien Force/Ultimate Alien]]
* AntiHero: Slides between Type II and Type III constantly. On rare occasion (like when dealing with Ragnarok), he goes Type IV.
* TheAtoner
* TheBigGuy
* BookDumb: Plays at this, but is in fact ''not''. Gwen notes that he's good at math and a top-notch engineer, as well as having a knowledge of history. It helps that he literally hasn't gone to school since the age of 11, and most of what he knows he learned on the streets by doing rather than from books by studying.
* ComboPlatterPowers
* CoolCar
* DeadpanSnarker
* EasilyForgiven: Only recently has any mention been made of his prior characterization ("criminally insane"). However, there were signs of Ben questioning his trust in the first few episodes until he trusted him entirely. Although given that he antagonized Ben for a whole season, you think it would've taken just as long to have Ben forgive him, not just a fraction of a season.
** Like much of the AuthorsSavingThrow involved with Kevin in ''Ultimate Alien'', this is attempted to be explained with a rather convoluted explanation about Ben's subconsciousness and involving Paradox.
*** He [[spoiler: gets hit with this trope AGAIN in the Ultimate Alien Season One finale. Energy-induced insanity or not, he literally is forgiven for what the crap pulled after one simply "Sorry, man." See KarmaHoudini below.]]
* ExtraOreDinary[=/=]ChromeChampion: Capable of turning his body into various metals and/or solid materials that he touches, due to being part Osmosian.
* FreakOut: When he's transformed again in ''Alien Force'' after he and Ben (unsuccessfully) attempted to hack the Omnitrix. [[spoiler: And once more in ''Ultimate Alien'' after absorbing the aliens in the Ultimatrix]].
* HeroicWillpower: A flashback in ''Ultimate Alien'' reveals he had to concentrate to get back to normal from his transformation in the original series.
* HeroicSacrifice: Non-fatal example. [[spoiler: He saves the universe and defeats Aggregor, but at the cost of his sanity.]]
* IfYouKillHimYouWillBeJustLikeHim: "Vendetta". [[spoiler: He doesn't listen. [[CompleteMonster Not that Ragnarok didn't deserve it, though]].]]
* IndyPloy
* JamesBondage
* JerkWithAHeartOfGold
* KarmaHoudini: [[spoiler: While no-one wanted to see him get killed since he wasn't in total control of his action, the lack of any sort of permanent consequence for him after his vicious crimes while insane (major collateral damage, attempted murder, possible offscreen murder, etc.) is a little jarring.]]
** [[spoiler: Not to mention driven further home how everyone seemlessly forgives him after he makes a wisecrack the moment he's reverted back to normal.]]
* KickTheSonOfABitch: [[spoiler: Ragnarok.]]
* TheLancer
* LoveableRogue
* TheMcCoy
* MidseasonUpgrade: Gets shapeshifting powers in ''The Vengeance Of Vilgax'' which make him stronger, which he retains even after being restored to human form. Made a plot point in that if he hadn't got them, they'd have been unable to save the world from Hex. This ''really'' helps increase his usefulness to the team.
* MightyGlacier
* ShapeShifterModeLock: ''Alien Force'' Season 3
* [[MyNameIsInigoMontoya My Name Is Kevin Ethan Levin]]. YouKilledMyFather. PrepareToDie: [[ShoutOut Quoted verbatim]]. [[spoiler:Then invoked a second time in ''Ultimate Alien'' for his old mentor Kwarrel.]]
** [[WordOfGod According to]] DwayneMcDuffie, his mom read him ''Literature/ThePrincessBride'' as a child, [[IAlwaysWantedToSayThat so he's probably wanted to say that for the longest time]].
* RedemptionDemotion: Subverted. [[BadassDecay While not as badass]] [[TheWorfEffect as he used to be]], he's become smarter during the TimeSkip and continues to show it as he spends more time with Ben and Gwen. This especially shows halfway through ''Ultimate Alien'''s first season.
* ReformedCriminal: Mostly. By his own admission, he's not entirely trustworthy -- and a lot of the tech he has in the back of his ride is stolen. Though in his defense, most of the ones he stole from were enemies they were fighting.
* TheResenter: [[spoiler:When he goes insane again after absorbing the Ultimatrix's power]] Kevin reveals a great deal of resentment towards Ben. Ben always beat him when they were kids, Ben becomes a world famous superhero while Kevin gets turned into a monster, Ben gets a happy homelife...it's ''always'' Ben who gets everything. It's not really made clear how much of this [[spoiler:is just the energy-driven insanity]] speaking and how much of it is real.
* RoaringRampageOfRevenge: After being driven insane in Ultimate Alien he decides to go on one of these whenever he's not absorbing other peoples powers.
* RunningGag: His [[ThePreciousPreciousCar Precious Precious Car]] keeps on getting destroyed.
** [[CatchPhrase "Not my ride!"]]
* TallDarkAndHandsome
* TallDarkAndSnarky
* TeensAreMonsters: Inverted, he was evil as a child, but turned good after turn into a teenager.
* TroubledButCute
* VoluntaryShapeshifting
* TheWorfEffect: He's usually always the one who gets his ass kicked the most in battle.

!Rook
-> Voiced by Bumper Robinson

Ben's new partner in Ben10Omniverse, sent by Max to team up with him after Kevin and Gwen had to leave for still unknown reasons. Despite being an alien, Rook possess no special powers, instead relying on a device called the Prototon that can transform into various weapons and equipment.

* AscendedFanboy: he appears to have quite admiration for Ben.
* BadassNormal: he lacks any power, relying only on hight technology; however, judging by the preview, this doesn't stop him from being a quite good fighter.
* ByTheBookCop: Rook is described as "all training no experience".
* {{Foil}}: to Ben; he is a ByTheBookCop with no actual experience, in contrast with Ben being TaughtByExperience with few training. Moreover, he relies on technology, while Ben relies on alien biological abilities.
* GadgeteerGenius

!Maxwell "Grandpa Max" Tennyson
-> Voiced by Paul Eiding

* {{Adorkable}}: Back when he first met Verdona, he managed to hit this trope ''while still being badass''. The early 1960s setting- so early that one would think it to be fifties if not for the Kennedy reference- definitely helped.
* BadassGrandpa
* BadassNormal: he is probably by far the most competent Plumber ever.
* BigGood
* CommutingOnABus: Doesn't appear as often after the original series. Justified in that Ben and Gwen don't need him as much now that they're older.
* CoolCar
* GadgeteerGenius
* HeroesWantRedHeads: As evidenced by Verdona in the WholeEpisodeFlashback.
* IWasQuiteALooker: In the flashback episode to his early years, he fulfills this trope in spades. Yum yum.
* TheKirk: Of the original series.
* LethalChef
* TheMentor
* TheMenInBlack: The Plumbers
* MissedTheCall: The Omnitrix was sent to Earth with the intent of ''Max'' finding it, not Ben.
* TheObiWan: [[NotQuiteDead Subverted]].
* ReasonableAuthorityFigure
* RetiredBadass: Well, ''formerly'' retired.
* TwoRoadsBeforeYou: Had the chance to be the first man on the moon, but then he was approached to join a certain interstellar organization.
[[/folder]]

[[folder: The Omnitrix and Ultimatrix]]
-> Voiced by YuriLowenthal

* BlackBox
* ClingyMacGuffin: [[spoiler:Though by the last season of Alien Force this is no longer true, as Ben knows exactly how to remove the thing whenever he wants. He just doesn't want to.]]
* DeeBradleyBaker: Unless stated otherwise, [[ManOfAThousandVoices this guy]] voices ''all the aliens'' introduced after ''Alien Force'' and replaces most of the alien voices from the original series.
** He's probably breathing a sigh of relief since he's not gonna have to massively overwork himself/run out of different voices in ''Omniverse'', considering Bumper Robinson, JohnDiMaggio, DavidKaye and YuriLowenthal are going to voice some of the aliens along with other unannounced voice actors.
* DiscardAndDraw
* EmpathicWeapon
* ImportedAlienPhlebotinum
* LoyalPhlebotinum
* MagicalComputer
* MagicalDatabase: The Codon Stream
* SelfDestructMechanism: Depending on how long it's charged, it could blow a person's arm off (that is, unless they're MadeOfIron) or destroy the whole damn universe.
* {{Shapeshifting}}
* SuddenlyVoiced: By YuriLowenthal from ''Alien Force'' onward.
* SuperWristGadget
* SuspiciouslySimilarSubstitute: [[TheSameButMore The Ultimatrix]]
* TransformationTrinket

!Current Ultimatrix Playlist

Aliens Ben uses in ''UltimateAlien''.

!! '''Alien X''' (AF-13)
-> Serena voiced by Vicki Lewis (Alien Force), TaraStrong (Ultimate Alien)
-> Bellicus voiced by KevinConroy (Alien Force), JeffBennett (Ultimate Alien)

* AwesomeButImpractical
* ChekhovsGunman: Played a role in ''Ultimate Alien'' episode 16.
* FreudianTrio: Serena is the [[TheSpock Superego]], Bellicus is the [[TheMcCoy Id]], and Ben is the [[TheKirk Ego]].
* TheLoad
* RealityWarper
* StarSpangledSpandex
* [[SealedEvilInADuel Sealed Neutral in a Debate]]
* SealedGoodInACan: Ben had the alien locked in the Ultimatrix so that it can only be activated for emergencies, and so Albedo couldn't access it were he ever to get his hands on a Codon reciever again.
* VoiceOfTheLegion: When he ''does'' speak, it's Bellicus, Serena, and Ben in unison.

!! '''[=AmpFibian=]''' (UA-08)
-> Voiced by YuriLowenthal (in "Fused"), DeeBradleyBaker

* ElectricJellyfish: An anthropomorphic version.
* ElectronicTelepathy
* FragileSpeedster
* IntangibleMan
* ShockAndAwe

!! '''Armodrillo''' (UA-09)
-> Voiced by DeeBradleyBaker (Ultimate Alien), JohnDiMaggio (Omniverse)

* DishingOutDirt
* MightyGlacier
* PoweredArmor: Appearance-wise, but it's organic.
* SuperStrength

!! '''Big Chill/Ultimate Big Chill''' (AF-04, UA-03)
-> Voiced by DeeBradleyBaker

* AnIcePerson
* BreathWeapon
* {{Fauxshadow}}: One episode has him going out of Ben's control, and Gwen believes that he's following in the footsteps of Ghostfreak, since they're both ghost-like aliens. But actually, no, BC was just getting ready to be a mommy/daddy/whatever.
* GlassCannon: Unless he's using his intangibility.
* HarmlessFreezing: Unless Ben engaged in a major BloodlessCarnage slaughterfest in "Hit 'Em Where They Live", BC's ice is like this.
* MisterSeahorse: Every 70 Earth years or so.
* OurGhostsAreDifferent
* TechnicolorFire: Reversed. Big Chill blows blue ice breath, while [[SuperMode Ultimate Big Chill]] breathes red [[BreathWeapon "ice flames"]] that create an instant [[strike:ice sheet]] ''glacier''.
* WingedHumanoid: Specifically moth-like wings.

!! '''Brainstorm''' (AF-07)
-> Voiced by DeeBradleyBaker (Alien Force and Ultimate Alien), CoreyBurton (Omniverse)

* BritishAccent
* [[StarfishAliens Crawfish Alien]]
* [[GiantEnemyCrab Giant Hero Crab]]
* MightyGlacier
* MyBrainIsBig
* SesquipedalianLoquaciousness
* ShockAndAwe
* TheSmartGuy

!! '''Cannonbolt/Ultimate Cannonbolt''' (OS-15, UA-06)
-> Voiced by FredTatasciore (Original Series), DeeBradleyBaker (Alien Force and Ultimate Alien), DavidKaye (Omniverse)

* [[BackForTheFinale Back For the Season Finale]]: Made its ''Alien Force'' debut in "War of the Worlds".
* EverythingsBetterWithSpinning: Though it's a forward thrust thing, not just in place like a top.
* FredTatasciore: His voice in the original series.
* GrievousHarmWithABody: Namely, his own.
* HyperDestructiveBouncingBall
* PromotionToOpeningTitles: in the original series, replacing Ghostfreak.
* RollingAttack
* StoneWall: Cannonbolt
** LightningBruiser: Ultimate Cannonbolt
* UnbreakableWeapons: His shell has been shown, on at least one occasion, to withstand being stabbed by Petrosapien crystal.
** Don't forget the time he survived falling back to the Earth from re-entry!

!! '''[=ChamAlien=]''' (UA-32)
-> Voiced by DeeBradleyBaker

* BewareMyStingerTail
* FragileSpeedster
* {{Invisibility}}
* CheshireCatGrin
* GlamourFailure: When invisible, he still casts a shadow.
* ShoutOut: Chamalien could be called the shout out alien:
** His design and powers are similar to Randall from WesternAnimation/MonstersInc.
** His three eyes are based on the 50s film version of WarOfTheWorlds
** His Grin powers and colors could be a reference to the Cheshire Cat.
* SlasherSmile

!! '''Chromastone/Diamondhead''' (AF-05, OS-01)
-> Chromastone voiced by DeeBradleyBaker
-> Diamondhead voiced by Jim Ward (Original Series), DaranNorris (Race Against Time), DeeBradleyBaker (Alien Force, Ultimate Alien), Eric Bauza (Omniverse)

* EnergyAbsorption: Chromastone
* GemstoneAssault: Diamondhead
* GlassCannon: Diamondhead
* HealingFactor
* LightEmUp: Chromastone
* LightningBruiser: Chromastone
* NighInvulnerability: "Nigh" is the keyword, at least for Chromastone.
* PowerCrystal: Living ones at that.
* ShapeshifterWeapon: Diamondhead
* StealthPun: Diamondhead ''is'' durable, but he can crack under enough pressure. He's a GlassCannon!
* SuspiciouslySimilarSubstitute: Chromastone to Diamondhead, then vice-versa.

!! '''Clockwork'''
-> Voiced by DeeBradleyBaker

* BlingOfWar: Except he's the SquishyWizard in practice.
* ClockworkCreature
* GlassCannon: His lasers can age you to dust in seconds, but one blast that other forms just shrug off is enough to knock him out and break his arm.
* PensieveFlashback: Another ability of his is casting holograms of past events over the location where they happened, through whomever is around.
* TimeMaster

!! '''Eatle''' (UA-42)
-> Voiced by DeeBradleyBaker (Ultimate Alien), Eric Bauza (Omniverse)

* BigCreepyCrawlies: Looks like a giant rhinoceros beetle.
* ExtremeOmnivore
* HornAttack: It can shoot beams after consumption.
* TheWorfEffect: Doesn't get a chance to ''do'' anything in his first appearance before getting clobbered.

!! '''Echo Echo/Ultimate Echo Echo''' (AF-02, UA-11)
-> Voiced by DeeBradleyBaker

* AttackDrone: Ultimate Echo Echo trades the DoppelgangerAttack for a series of floating discs that act as speakers for his sonic attacks.
* CombinationAttack: [[ExactlyWhatItSaysOnTheTin "Wall of Sound"]].
* DoppelgangerAttack: Echo Echo
* {{Flight}}[=/=]SuperSpeed: Ultimate Echo Echo is the only alien faster than Jetray or [=XLR8=].
* JackOfAllStats: Echo Echo
** LightningBruiser: Ultimate Echo Echo
* MakeMeWannaShout: His basic form of attack.
* MechanicalLifeforms: He's a silicon-based lifeform, so he's most likely one.
* MesACrowd: Unlike Ditto, however, the duplicates are not constantly synced to each other, so it is possible for each one to transform into different forms separately, as seen in episode 2 of the newest series. Unfortunately, [[WordOfGod Ultimate Echo Echo is incapable of this]].
* RoboSpeak: Sounding like a speech synthesizer as Echo Echo, but loses any inflection and goes straight into CreepyMonotone as Ultimate Echo Echo.

!! '''Fasttrack''' (UA-28)
-> Voiced by DeeBradleyBaker

* LightningBruiser: Confirmed to be stronger than [=XLR8=]
* SuperSpeed
* SuspiciouslySimilarSubstitute: Of [=XLR8=].

!! '''Four Arms''' (OS-02)
-> Voiced by Richard [=McGonagle=] (Original Series), DeeBradleyBaker (Ultimate Alien), JohnDiMaggio (Omniverse)

* BadassLonghair: In ''Ultimate Alien''
* TheBigGuy
* DestructiveSavior: He's got super strength, but can't control it sometimes.
* LeeroyJenkins: Most notable in the first series, when ever Ben would act incredibly impulsive during a fight, chances are he'd turn into Four Arms.
* LightningBruiser
* MultiArmedAndDangerous: He has four arms. Duh.
* PunnyName: Forearms = Four Arms = 4 arms
* SuperStrength
* SpotlightStealingSquad: Ben's favorite alien in the original series.
* VocalEvolution: Richard [=McGonagle=] uses a deep growling voice early on in season 1 of the original series. By season 2, he uses the higher gargling tone Four Arms is known for.

!! '''Ghostfreak''' (OS-04)
-> Voiced by SteveBlum (Original Series), JeffBennett (Alien Force, Ultimate Alien)

* AndIMustScream: Unlike other species sampled for the Omnitrix, even the smallest sample of DNA contains an Ectonurite's consciousness. A copy of Zs'Skayr's consciousness was subsequently trapped inside the Omnitrix and ''fully aware the entire time''.
* ConfusionFu
* IntangibleMan
* NamesTheSame: Zs'Skayr goes by the same name in-series, but he and Ghostfreak are (sort of) different characters.
* OurGhostsAreDifferent

!! '''Goop''' (AF-09)
-> Voiced by DeeBradleyBaker

* BlobMonster
* ConfusionFu
* CoveredInGunge: Not him, but others when he takes a hit.
* HollywoodAcid: Can make his substance this to attack.
* NighInvulnerability: By way of being Made of Fluid. (See BlobMonster)
* ThisLooksLikeAJobForAquaman: His usefulness is limited in battle, but finds practical uses in other areas, such as saving a planet from being split apart.
* VoluntaryShapeShifting: To a point. He can flow through any opening his little saucer can get through.
* WeaksauceWeakness: Take away his saucer, and he's immobilized. Ben uses this to get the Omnitrix back from Vilgax on Primus.

!! '''Heatblast''' (OS-01)
-> Voiced by SteveBlum (Original Series), DeeBradleyBaker (Ultimate Alien), DavidKaye (Omniverse)

* ElementalPowers
** AnIcePerson: Temporarily, when Ben catches a cold and it spreads to his alien forms.
** MagmaMan: Literally
** PlayingWithFire
** ThePowerOfTheSun: What with Pyronites being born on stars and all.
* JackOfAllStats

!! '''Humongousaur/Ultimate Humongousaur''' (AF-02, UA-06 [[hottip:*:Although he was used by Albedo in AF-45]])
-> Voiced by DeeBradleyBaker (Alien Force, Ultimate Alien), JohnDiMaggio (Omniverse)

* AttackOfThe50FootWhatever: Can grow to 60 feet.
* EverythingsBetterWithDinosaurs
* MadeOfIron: Took lasers and missiles directly and only staggered.
* MightyGlacier
* SizeShifter: Humongousaur.
* WeaponOfChoice: As Ultimate Humongousaur.
** EpicFlail: Has a [[BewareMyStingerTail club-tail]] like an [[http://en.wikipedia.org/wiki/Ankylosaur Ankylosaur]], only his has a mace-like spiked ball.
** MoreDakka: Can turn his hands into four-barrel rocket launchers.

!! '''Jetray''' (AF-03)
-> Voiced by DeeBradleyBaker

* BewareMyStingerTail
* EyeBeams: And tail beams, too.
* FasterThanLightTravel: He can apparently generate his own [[Franchise/StarTrek warp field]].
* {{Flight}}
* FragileSpeedster
* [[BatmanCanBreatheInSpace Jetray Can Breathe In Space]]
* SuperSpeed: In the skies and underwater, but not on land.

!! '''Jury Rigg'''
-> Voiced by DeeBradleyBaker (Ultimate Alien), Bumper Robinson (Omniverse)

* GeniusDitz: When fixing things rather than breaking them.
* GripingAboutGremlins
* MrFixit
* [[TokenEvilTeammate Token Uncontrollable Alien Form]]: His basic instict is to break technology, which Ben doesn't have much control over.

!! '''Lodestar''' (AF-31)
-> Voiced by DeeBradleyBaker

* [[FromASingleCell From A Single Magnet]]
* IncomingHam: "LOOOODESTAAAAARR!!"
* InvisibleAnatomy: His head seems to be nothing more than a metal ball held up by a magnetic field, but his body comes along if it's moved.
* PullingThemselvesTogether: Does it when he gets blown up in "Ultimate Aggregor".
* RaymanianLimbs: his head.
* RoboSpeak: Like Echo Echo, he has a synthesizer-voice.
* SelectiveMagnetism
* StoneWall

!! '''Nanomech''' (Alien Swarm)
-> Voiced by Alex Winter (Alien Swarm), DeeBradleyBaker (Ultimate Alien)

* CanonImmigrant: While the other movie alien (Eon) has been absent since TheMovie, Nanomech has made the transition to the cartoon.
* CyberCyclops
* HeliumSpeech: For ''Ultimate Alien'', to go with his microscopic stature.
* HiveMind: In ''Alien Swarm'', turning into Nanomech made him hear the voice of the Queen. Luckily, he resisted.
* IncredibleShrinkingMan: And he ''starts'' at about an inch.
* LethalJokeCharacter
* MechanicalLifeforms
* WingedHumanoid: He has four bug-like wings. The show forgot the first time for no apparent reason, but they remembered later.

!! '''NRG''' (UA-16)
-> Voiced by DeeBradleyBaker

* ElementalPowers
** ILoveNuclearPower
** PlayingWithFire: Uses "heat", not necessarily "fire".
* EnergyBeing
* {{Lzherusskie}}
* MightyGlacier
* PoweredArmor

!! '''Rath''' (AF-39)
-> Voiced by JohnDiMaggio

* BadassNormal: Aside from his claws, the only thing Rath has is his strength and he ''still'' manages to be one of Ben's most powerful aliens.
* BoisterousBruiser
* CallingYourAttacks: In the form of Constellation/Star + wrestling move--"Polaris Pile Driver!"
* CatchPhrase: "Lemme tell ya somethin', ([[FullNameUltimatum full name here]])..."
* DestructiveSavior
* DumbMuscle
* {{Expy}}: Pretty obviously a tiger version of Hulk Hogan.
* HairTriggerTemper: He's practically this trope personified.
* [[ImmuneToBullets Immune To Lasers]]: It just makes Rath ''mad!''
* JerkJock
* JerkWithAHeartOfGold
* LargeHam
* LightningBruiser
* LeeroyJenkins
* MeaningfulName: (W)Rath, the "Apoplexian". Doesn't get much more obvious than that.
* MegaNeko: What? He looks like a big anthro tiger.
* TheNicknamer: Calls Technorg, "Baby Man", and Seven-Seven "Karate Man".
* NinjaPirateZombieRobot: An alien who looks like a tiger and fights and acts like a wrestler. That sums him up.
* NoIndoorVoice: Subverted once when he answered a phone and lowered his voice. Otherwise, he's never quiet.
* NighInvulnerable: Getting hit with a laser doesn't phase him, nor does dropping out of the sky and causing a giant crater of him knock him out.
* PapaWolf: After warming up to the Tiffin. To the point that he'd ''knit a sweater out of an alien's organs'' if it declared war.
* SuperStrength
* ThirdPersonPerson: Additionally, addresses people by full name or title.
* {{Tsundere}}: Male example, possibly parodied; he has a soft spot for his friends, but usually blows them off with a "Whatever!"
* UnstoppableRage: Basically exists in this state.
* WhenAllYouHaveIsAHammer: Kevin notes that all of Rath's species believes that anything can be solvable by hitting it.
* WolverineClaws: Except he only has one on each hand. [[GettingCrapPastTheRadar In the middle of them]].
* WrestlerInAllOfUs

!! '''Ripjaws''' (OS-03)
-> Voiced by FredTatasciore (Original Series), DeeBradleyBaker (Ultimate Alien)

* AlluringAnglerfish
* JokeCharacter[=/=]LightningBruiser: He's the former on dry land, but in water, he becomes the latter.
* MoreTeethThanTheOsmondFamily
* SuperNotDrowningSkills
* ThisLooksLikeAJobForAquaMan: Used almost specifically for aquatic environments, and is useless anywhere else.
** One of the last times he was seen in the original series was when Ben used him in a beach episode. Surfing.
** Although occasionally this could be subverted, as shown in Ripjaws last appearence in the Original series, where he proceeded to start tearing chunk out of a bad guy's car, despite being in the desert and the car MOVING.
* WeaksauceWeakness: He can't survive without water for long. As a result, he is one of Ben's least used aliens.

!! '''Shocksquatch''' (Ben 10 & Generator Rex: Heroes United)
-> Voiced by DavidKaye

* CanadaEh: Speaks with this accent, eh?
* BigfootSasquatchAndYeti
* ShockAndAwe
* SuspiciouslySimilarSubstitute: Brainstorm, minus the super-intelligence.
* YouDontLookLikeYou: In ''HeroesUnited'', he looks like a fairly normal-looking [[http://images.wikia.com/ben10/images/8/80/Screenshot2011-11-25at83224PM.png yeti]]. In ''Omniverse'', he looks [[http://images.wikia.com/ben10/images/5/50/ShocksquatchAlien.jpg far more]] like a typical [[ShockAndAwe electric]] character, to the point he resembles a simian [[SpiderMan Electro]].

!! '''Spidermonkey/Ultimate Spidermonkey''' (AF-08, UA-01)
-> Voiced by DeeBradleyBaker

* BreathWeapon: His Ultimate form shoots webbing from his mouth.
* [[EverythingsBetterWithMonkeys Everything's Better With Arachnichimps]]
* FragileSpeedster: Spidermonkey
** LightningBruiser: Ultimate Spidermonkey
* MultiArmedAndDangerous: Spidermonkey
* SuperStrength: Ultimate Spidermonkey
* WallCrawl

!! '''Swampfire/Ultimate Swampfire''' (AF-01, AF-46)
-> Voiced by DeeBradleyBaker

* ComboPlatterPowers: Basically Wildvine with a touch of Heatblast.
* CuteLittleFangs: Though only visible when up-close ([[http://images4.wikia.nocookie.net/__cb20110426073635/ben10/images/1/1c/Swampfire10.png as seen here]]), they're most notable at the start of "Prisoner 775".
* DisneyDeath: Both were briefly lost in the battle against Eon, who turned them to dust, but were "revived" by Ben 10,000 at the end.
* ElementalPowers
** GreenThumb
** PlayingWithFire
* HealingFactor: Swampfire
* KamehameHadoken: Ultimate Swampfire can shoot a large blast of blue flames from his palms
* LightningBruiser
* PlantAliens
* WhenTreesAttack: Ultimate Swampfire

!! '''Terraspin''' (UA-12)
-> Voiced by DeeBradleyBaker (Ultimate Alien), Bumper Robinson (Omniverse)

* AntiMagic: The species is immune to mana. Pity Ben fails to remember the fact the ''one time'' it would have helped.
* BlowYouAway
* EverythingsBetterWithSpinning: How he generates his wind attacks.
* JohnDiMaggio: Voice actor for his DNA doner, Galapagus, but not Terraspin himself.
* StoneWall
* TurtlePower

!! '''Upchuck''' (OS-39)
-> Voiced by DaveWittenberg (Original Series), DeeBradleyBaker (Alien Force, Ultimate Alien), Eric Bauza (Omniverse)

* BigEater: Except he can't digest what is normally considered "food", leading to...
** ThisBillboardNeedsSomeSalt: At one point, he drinks an animated "Mr. Smoothie".
*** In the original series, this is quoted as Ben exclaims that Upchuck is a bottomless pit, but just can't eat regular food.
* BreathWeapon: Upchuck can fire laser beams from his mouth (or as he called them in Upchuck's debut 'exploding loogies'), though it has only been used twice (first against the Forever King in the original series then later on against Chromastone (who had escaped from the Omnitrix) in alien force. Though he prefers to fire exploding green energy pellets instead.
* ExtremeOmnivore
* GlassCannon
* MeaningfulName: When he showed off his powers of 'exploding loogies', Ben exclaimed that he had 'Upchuck power', that is to say, acidic vomit.

!! '''Upgrade''' (OS-04)
-> Voiced by TaraStrong (Original Series), YuriLowenthal (Ultimate Alien)

* ConfusionFu[=/=]MightyGlacier: He's the latter when he's just Upgrade and the former when....everything else.
* CyberCyclops
* MechanicalLifeform
* RoboSpeak: Averted, Ben retains his human voice in this form, albeit with some static noises in the background.
* {{Technopath}}

!! '''Water Hazard''' (UA-01)
-> Voiced by DeeBradleyBaker

* LightningBruiser
* MakingASplash
* NighInvulnerability

!! '''Way Big''' (Secret of the Omnitrix [[hottip:*:Part 3, or technically OS-52]])/Ultimate Waybig (UA-52)
-> Voiced by FredTatasciore (Original Series), DeeBradleyBaker (Alien Force, Ultimate Alien)

* AttackOfThe50FootWhatever
** SummonBiggerFish
* DestructiveSaviour: His energy beam as Ultimate does not automatically shut off if he moves.
* DisneyDeath: Was aged to dust by Eon, but restored by Ben 10,000.
* {{Expy}}: Of {{Ultraman}}. Right down to the + style energy beam.
* KamehameHadoken
* MightyGlacier[=/=]LightningBruiser: Originally the former, but turned out to be the latter.
* ShoutOut: Has horns like UltramanTaroh but the color scheme of UltramanTiga and UltramanDyna.
** SpinToDeflectStuff
** FourFingeredHands
* SuperSpeed
* WeaponOfChoice: As Ultimate Way Big.
** BladeBelowTheShoulder
** RingsOfDeath: As an EnergyWeapon.

!! '''Wildmutt/Ultimate Wildmutt''' (OS-01, UA-32)
-> Voiced by DeeBradleyBaker

* AngryGuardDog: With ape arms.
* BadassNormal: Compared to the other aliens, at least.
* BewareMyStingerTail: Ultimate Wildmutt gains a spiked tail.
* [[CallASmeerpARabbit Call A Vulpamancer A Dog]]
* TheCameo: Made a brief appearance in "Victor: The Spoils", while Ben was unconscious, before making his official reappearance in "Prisoner 775 is Missing".
* DisabilitySuperpower: Has no eyes but can "see" with it's other senses.
* EarlyBirdCameo: Meta example; a toyline first revealed the existence of Ultimate Wildmutt.
* JackOfAllStats: Wildmutt
** LightningBruiser: Ultimate Wildmutt.
* SkunkStripe: Ultimate Wildmutt has one down his back. It's even got a black outline where it attaches to his back, making it more obviously this trope.
* TheVoiceless: Averted with Ultimate Wildmutt, who is able to talk.

!Aliens Unused Since Alien Force

Since the Ultimatrix is just [[TheSameButMore a better Omnitrix]], most of these have been confirmed to be in it, but not accessed yet.

!! '''Benmummy''' (OS-37)
* CombatTentacles: The bandages that make up his body
* ConfusionFu: Needless to say he has a very unorthedox attack pattern.
* {{Mummy}}
* NighInvulnerable: Can easily be torn apart and even ''shredded to bits'', but could reform nearly instantly.
* OneShotCharacter: Although he did make a brief appearance as a ContinuityNod in a later episode.
* SuddenlyVoiced: Ben can speak as Benmummy, despite the fact that the alien he got the DNA sample from is TheVoiceless.
* ZombieGait: Averted -- he's actually one of the more nimble aliens Ben can use.

!! '''Benviktor''' (OS-38)
-> Voiced by Michael Dorn

* {{Expy}}: Of both Dr. Frankenstein ''[[CompositeCharacter and]]'' [[FrankensteinsMonster his monster]].
* GeniusBruiser
* MadScientist
* MightyGlacier
* OneShotCharacter
* ShockAndAwe
* ShoutOut: To MaryShelley's ''Frankenstein''.

!! '''Benwolf''' (OS-31)
-> Voiced by TaraStrong

* LightningBruiser
* MakeMeWannaShout: Or howl, to be more precise
* OneShotCharacter
* [[OurWerewolvesAreDifferent Our Werewolves Are Aliens]]
* SuddenlyVoiced: See above.

!! '''Ditto''' (OS-41)
-> Voiced by RobPaulsen

* TheArtifact: Echo Echo pretty much makes this guy obsolete.
* BadassAdorable: An adorable alien that's around the height of a kid who likes praying pranks. However it was used to destroy an army of mutant bugs in its debut episode.
* DoppelgangerAttack
* LethalJokeCharacter
* MesAcrowd
* TalkingToHimself: In a literal sense.
* WeakButSkilled
* WeaksauceWeakness: The clones all feel each other's pain. If one dies...

!! '''Eon''' (Race Against Time)
[[AC:See Villains section]]

!! '''Eye Guy''' (OS-48)
-> Voiced by DeeBradleyBaker

* EarlyBirdCameo: Appeared in an alternate scene of ''Secret of the Omnitrix'''s opening scene but chronologically appeared first in "Ben 10 vs. The Negative 10, Part 2".
* ExtraEyes: Has eyes everywhere...
** EyesDoNotBelongThere: [[{{Irony}} Except where they should be]].
* EyeBeams: Every eye can fire a laser beam. Some eyes have a different type of laser.
** AnIcePerson: Can fire an ice laser.
** FrickinLaserBeams
* LightningBruiser

!! '''Grey Matter''' (OS-02)
-> Voiced by RichardStevenHorvitz (Original Series), Eric Bauza (Omniverse)

* GadgeteerGenius
* HeyItsThatVoice
* IncredibleShrinkingMan: Ben goes from whatever size he normally is, to about 6 inches tall.
* LethalJokeCharacter
* ShorterMeansSmarter
* TheSmartGuy
* WallCrawl
* WhatKindOfLamePowerIsHeartAnyway: At least in Ben's opinion. Though as the series went on, he found practical uses for him.

!! '''Stinkfly''' (OS-02)
-> Voiced by DeeBradleyBaker

* BigCreepyCrawlies
* BreathWeapon: Shoots slime from his mouth.
* {{Flight}}
* GlassCannon: Seriously, just throw some [[WeaksauceWeakness water]] on this guy and he's through.

!! '''Wildvine''' (OS-20)
-> Voiced by Jim Ward

* GlassCannon
* GreenThumb
* PlantAliens

!! '''[=XLR8=]''' (OS-01)
-> Voiced by Jim Ward

* EverythingIsBetterWithDinosaurs: Looks like an armored velociraptor with wheels as his feet.
* FragileSpeedster
* InformedFlaw: According to the Bandai profile, his species has problem running on water due to the static electrity they produce while moving. Yet, [=XLR8=] has been seen walking on water with no such problems. Fans usually assume the suit might be protecting him.
* OurElvesAreDifferent: The bandai profile describes his species has possessing PointyEars and long hair, much like elves. However, since [=XLR8=] wears a helmet and can't remove it (and so does Helen), this has never been confirmed. On a note, the shape of his helmet is reminiscent of the Eldars, aliens from Warhammer40000 who are basically elves in space.
* SuperSpeed

! Aliens that will debut in ''Ben10Omniverse''

!! '''Ball Weevil''' (OV-??)
* BigCreepyCrawlies: Although he isn't THAT big.

!! '''Bloxx''' (OV-??)
-> Voiced by Bumper Robinson

* BuiltWithLego: No, really.
* OurMonstersAreWeird: Again, he's a gorilla ''made from living LEGO bricks''.
* RubberMan
* VoluntaryShapeshifting: He's basically PlasticMan made out of LEGO bricks.

!! '''Gravattack''' (OV-??)
-> Voiced by DavidKaye

* GravityMaster: His name kind of gives this away.

!! '''Feedback''' (OV-??)
-> Voiced by YuriLowenthal

* EnergyAbsorption: He can absorb energy...
** EnergyWeapon: And then he can use it as a weapon!

[[/folder]]


[[folder: Villains]]

!Vilgax
-> Voiced by SteveBlum (Original Series), James Remar (Alien Force, Ultimate Alien)

* ArchEnemy: To Ben. Runs in the family, before Ben, he considered Ben's grandfather Max his archenemy.
** To the point that in the GrandFinale of ''Ultimate Alien'', Ben is more worried about Vilgax than he is about ''[[EldritchAbomination Diagon]]''. [[spoiler:And rightly so.]]
* BigBad: Original series season 1,Secondary Big Bad in Seasons 2,3,& 4, ''Secret of the Omnitrix'' movie, and ''Alien Force'' season 3. [[spoiler:He also serves as the TrueFinalBoss of ''UltimateAlien''.]] Basically for the entire series.
* {{Cthulhumanoid}}: Worth note is he's actually mistaken for another Great Old One in ''Ultimate Alien''.
* DidntSeeThatComing: His biggest flaw. His defeats ''always'' result from something he didn't expect to happen and he has difficulty dealing with it when it happens.
* TheDreaded: Is considered the most dangerious being in the entire universe and feared by nearly everyone. The only time anyone ''hasn't'' feared him was [[EldritchAbomination Diagon]], who Ben was ''less'' worried about than Vilgax. [[spoiler:[[EvilerThanThou And rightly so.]]]]
* {{Expy}}: To some degree, both series may have been trying to model him off of Darkseid, with the first series having a generally merciless murderer, and was ''feared'' by almost everyone in the galaxy, in Alien Force, he owns his own world, and even has what seem like the Omega Beams.
** He also seems to be an Expy of Cthulhu, as he has a head of an octopus and green skin but has no wings, but unlike Cthulhu, he is being mistaken for another Great Old One rather then being ''a'' Great Old One.
* GalacticConqueror
* JokerImmunity: No matter what, he is going to survive whatever life-threatening danger he's gotten into, whether it be a nuclear explosion or being thrown into space (though his implants make that one outright plausible). Even in a future where he was ''literally torn to pieces'', he's just brought back to life. [[AllThereInTheManual The Omnifacts, however, confirm that Vilgax will meet his end approximately 200 years in the future]].
** It was actually lampshaded by Ben in the Alien Force finale:
---> '''Ben''': He has survived worst [than his own ship's explosion].
** And again in the Ultimate Alien finale.
--->'''Kevin''': I thought Vilgax was dead.
--->'''Ben''': Which time ?
* KnightOfCerebus: Any episode he had some sort of presence in, the tone would become less humorous. A little less so in Alien Force, but again in Ultimate Alien.
* MadeOfIron: He survived a point-blank ''nuclear explosion'', and that was ''before'' he got enhanced!
* [[BatmanCanBreatheInSpace Vilgax Can Breathe in Space]]

[[AC:Original Series]]
* {{Badass}}: well, he has moments of this in all three shows, but most fans agree he was at his best in the original show.
* DangerouslyGenreSavvy: He spent a lot of time studying the Omnitrix, giving him the ability to turn it off whenever he wants to. He also exploits Ben's inability to not go to areas where evil's afoot. Most of the time he fails is because, as detailed above, [[DidntSeeThatComing something that he never expected happens]].
* EvilOverlord
* ImplacableMan
* LightningBruiser: He moves amazingly fast even after he uses the implants to make his arms stronger, which makes them swell up.
* SadisticChoice: In "Secrets", he attacks the Rustbucket and holds Gwen and Max hostage, and would only let them go if Ben handed himself over. Ben relented.
* VillainousBreakdown: It's subtle, but every time Vilgax appears after the season 1 finale, he's slightly more erratic, and he gets progressively more hellbent for the Omnitrix on Ben's wrist, then again, when you're a galactic overlord constantly getting beaten down by a kid, his grandpa, and his cousin, that does guarantee a breakdown.
** Made much more obvious in TheMovie. He goes from ''just'' going after the Omnitrix to being bent on killing Ben to get it. This is the result of him being thrown into the Null Void, which he displays a TwitchyEye whenever its mentioned. This goes so far that he turns up a chance to get the Omnitrix if he shuts down its self destruct (which he's probably smart enough to do so) and saves the universe because it doesn't involve killing Ben.
* WeCanRebuildHim: in his first appearance, he is almost killed by a beam from the ship he was following. It takes the whole season, but he is eventually repared and enhanced genetically and cybernetically, resulting in the look he has for most of the first series.

[[AC:Alien Force]]
* {{BFS}}: it can shoot beams, cut through diamond and coat itself with flame/ice, amongst other things.
* [[spoiler:EnemyMine: with Ben in ''Ghost Town'', to free his planet.]]
* EvenEvilHasStandards: [[SubvertedTrope subverted]]; his respect of the Galactic Code in ''Vengeance of Vilgax'' was, if anything, PragmaticVillainy, as it allowed him to easily conquer 10 worlds without wasting any ressource and gain several new powers in the process. In the following episodes, he has ''no problem'' breaking said code.
* KneelBeforeZod: attempted this on Ben in the finale [[spoiler:after he took the Omnitrix from him]]. It didn't work.
* MegaManning: Begins defeating heroes across 10 worlds and absorbing the powers of those he defeated.
* NobleDemon: it's implied in ''Ghost Town'' that he actually cares to some extent about his people. Unclear if he really was this or if it's just his VillainWithGoodPublicity status.
* OneWingedAngel: Though not quite as frightening as it could potentially be, as seen [[http://ben10.wikia.com/wiki/File:Vilgax_True_Form.png here.]] According to WordOfGod, he could always do this, but there weren't many situations were it would actually come in handy.
** Fortunately for him, this form happened to fit the description of the alien worshipped by the Flame Keepers Circle, allowing them to play them as pawns in Ultimate Alien.
* VillainWithGoodPublicity: Implied to have gone that route since the CardCarryingVillain persona didn't fare well for him. It worked out pretty well for him, as it let him conquer 10 worlds in a fairly short length of time.

[[AC:Ultimate Alien]]

* AGodIAm: Seeks to absorb the power of Diagon, the EldritchAbomination he'd been impersonating. [[spoiler:In the end, [[DidYouJustScamCthulhu he succeeds]].]]
* DealWithTheDevil: Makes a deal with Diagon, an EldritchAbomination, to free it from [[SealedEvilInACan its can]] in exchange for the power to conquer the universe. [[spoiler:Unfortunately for Diagon, he wasn't the devil in the deal.]]
* DevourTheDragon: [[spoiler:Somewhat Inverted. Kills and absorbs [[EldritchAbomination Diagon]] to take his [[AGodIAm god-like power for himself]], but Vilgax technically was TheDragon in the whole thing. However, Diagon was his UnwittingPawn the entire time, so it may have been played straight.]]
* [[spoiler:EvilerThanThou: Diagon realized too late that Vilgax was not to be underestimated.]]
* [[spoiler:DidYouJustScamCthulhu: he successfully manipulated Diagon by faking submission, letting him kill George and eventually use a machine brought by Psyphon to absorb him, gaining his powers.]]
* TheDragon: Becomes this to Diagon.
** TheStarscream: Ben [[GenreSavvy instantly realized]] Vilgax wouldn't submit to this unless he had ''something'' up his sleeve. [[spoiler:He was right, Vilgax let Diagon kill Sir George and beatdown Ben and company before stealing his power, absorbing Diagon in the process.]]
* EliteMooks: The Flame Keepers' Circle are a lot more dangerous than his old MechaMooks.
* ExactWords: Vilgax assures his most loyal follower that's he going to "transform" the Earth.
--> '''Vilgax:''' When I'm done with this planet, you won't recognize it!
* GodGuise: Was mistaken for the alien worshipped by the Flame Keepers' Circle, Diagon the Knowledge Bringer. He's just enough of a ManipulativeBastard to make complete use of this, gaining a group of very competent minions with UndyingLoyalty towards him. This does have a drawback, however, as only his OneWingedAngel form resembles Diagon and he can't revert to his normal form in their sight. Bonus points as Diagon is named after an actual pagan god and a [[EldritchAbomination Great Old One.]]
* HowTheMightyHaveFallen: Subverted. While he's lost his empire (since he was declared dead, it ended up crumbling without him) and is trapped on Earth, he's gained a legion of suprisingly competant and dangerous henchmen who have UndyingLoyalty towards him.
* [[spoiler: MacGuffinDeliveryService]]: [[spoiler: His obsession with gaining Diagon's power causes him to deliver its heart's power back to the EldritchAbomination, despite Ben warning him that him was being manipulated]].
* ManipulativeBastard: Weakened from his previous battle, he gladly played first the role of a sideshow freak to regain his strength and then as Diagon, an alien worshipped by the Flame Keepers' Circle, to get himself a personal cult of followers that would do absolutely anything he desired. He [[spoiler:even managed to trick Julie into working for him for a short time]].
** [[spoiler:In the end, it turns out [[DidYouJustScamCthulhu he was manipulating]] ''[[EldritchAbomination Diagon]]'' the entire time to steal his power.]]
** [[spoiler:And again after Ben defeated him and took Diagon's powers from him, he tried to corrupt Ben by convincing him to use it to go KnightTemplar. He almost succeeded.]]
* NiceJobFixingItVillain: [[spoiler:Diagon was crushing the heroes with little effort...until Vilgax made his move and absorbed his powers. His own ego pretty much does the rest.]]
* NotSoDifferent: Vilgax invokes this with Ben in the finale, claiming they both use power to impose their will on the universe.
* [[spoiler:OutGambitted: Diagon thought he was in control of Vilgax the entire time. He wasn't, Vilgax was really the one manipulating Diagon the entire time.]]

!Psyphon
-> Voiced by DeeBradleyBaker

* AvengingTheVillain: attempts this on Ben to avenge Vilgax's apparent death. He fails.
* TheDragon: to Vilgax.
* EvilGenius: he appears to be an brillant scientist and often is the one building devices for Vilgax.
* NotSoHarmlessVillain: for most of the series, he was a rather passive character, usually leaving his master do the fight while he sticked to scientist and servant purpose. During the episode where he attempts to avenge Vilgax, however, he proves to be a surprisingly effective fighter who can stand toe to toe with ''Ultimate Spider-Monkey''.
* RedEyesTakeWarning
* SmugSnake: he is extremely arrogant to anyone else than his master, including Ben.
* UndyingLoyalty: he is incredibly loyal to Vilgax, going as far as trying to avenge him after Ben apparently killed him, and kept serving him even after his empire falled apart. Considering Vilgax is not above threatening him occasionnally, this truly ''is'' loyalty.

!Dr. Aloysius Animo
-> Voiced by DwightSchultz

* BadassGrandpa: Not at Max's level, but he comes close.
* TheBeastmaster
* DudeWheresMyRespect: The reason for his StartOfDarkness.
* EvilGenius
* EvilutionaryBiologist: his trademark trait.
* GadgeteerGenius: this guy can build a machine to mutate animals and resurrect prehistoric beast from tools and pieces he got in the local market.
* HeyItsThatVoice: Wait, [[{{Chowder}} Mung Daal]]?!
* MadScientist
* NotSoHarmlessVillain: Though normally a joke, he often does step up his game. "Voided" and "It's Not Easy Being Gwen" come to mind.
* TookALevelInBadass: In ''Alien Force'', as D'void.

!Hex
-> Voiced by Khary Phyton

* ArchEnemy: Comes to see Gwen (or rather, "Lucky Girl") as this, though from a story perspective Charmcaster fits the role for her better.
* [[AbusiveParents Abusive Uncle]]: To Charmcaster, particularly in the original series.
* DarkIsEvil: WordOfGod says that his mana is black and red due to his evil soul.
* EvenEvilHasLovedOnes: Played with; he is ruthless and quite abusive to Charmcaster in the original series, but openly admits he does care about her in Ultimate Alien (though he still refused to come and help her, believing it was suicide). According to WordOfGod, their relationship is complicated.
* EvilAlbino
* EvilSorcerer
* EvilUncle
* FreudianExcuse: [[spoiler: The destruction of his people and home by Adwagia. Of course, as the DarkIsEvil example above shows, he let it get to him in a negative way much more than his niece Charmcaster did.]]

!Charmcaster [[spoiler: (Hope)]]
-> Voiced by KariWahlgren

* [[spoiler: AntiVillain: Between Type II and Type III. She lost her whole people and her father as a child, was forced to leave in a world where magic was almost entirely unknown and was raised by an [[AbusiveParents Abusive Uncle]] who ended up turning evil. And her whole motivation was to resurrect her father.]]
* ArchEnemy: To Gwen
* BastardUnderstudy[=/=]DeceptiveDisciple
* BlackMagicianGirl: "I don't respect ANYONE!"
* BrokenBird: [[spoiler: As of "Enemy of My Frenemy", even more broken than before.]]
* [[spoiler: CryCute: Happens frequently in ''Ultimate Alien''.]]
* [[DaddysLittleVillain Uncle's Little Villain]]
* DarkMagicalGirl: Was always a play on this trope, and became even moreso in ''Ultimate Alien''.
* [[spoiler: DealWithTheDevil: And that devil was DIAGON!]]
* DefrostingIceQueen: In "Where the Magic Happens", she becomes slightly more friendly to Gwen as the episode progresses. [[spoiler: Sadly undone by "Enemy of my Frenemy", which makes her more of a BrokenBird than before.]]
* [[spoiler:DimensionLord: She becomes the ruler of Ledger Domain after defeating Adwaita.]]
* DoWithHimAsYouWill: [[spoiler:In "Couples Retreat", after finding out Dark Star was just using her for her power, she takes it all away from him and leaves him at the mercy of the heroes.]]
* EnemyMine: Gwen convinces her to help them retrieve a piece of the Map of Infinity from her home before Aggregor does. [[spoiler: They fail.]]
* EvilCounterpart: To Gwen.
* FemmeFatale: In ''Alien Force''.
* FreudianExcuse: She was raised by her uncle, who is shown to regularly threaten her if she doesn't obey him. Gee, is it any wonder she turned out bad?
** [[spoiler: The fact that every other human from her home was killed, including her father, doesn't help any either.]]
* [[spoiler: HeelFaceRevolvingDoor: In ''Ultimate Alien''. She's bad, then good, then worse, then neutral but working toward becoming good.]]
* HotWitch
* [[spoiler: IChooseToStay: Takes the trio back home, but stays to fight for hers, aware that she'll be trapped.]]
* [[spoiler: KarmaHoudini: Sure, Gwen takes pity on the poor [[BrokenBird broken girl]], but ''no'' sort of lawful punishment after attempting mass genocide? Isn't that....odd? Though she ''did'' have the entire reason for everything she'd ever done give her a WhatTheHellHero speech and be put forever out of her reach, so it's likely that Gwen and the others decided that punishing her would just be cruel.]]
** In all fairness, [[spoiler: she does have power on a level exceeding Gwen's at her command. Perhaps it felt it best not to provoke her when she had just killed all three of them without a sweat.]]
* KickTheSonOfABitch: She betrayed her uncle for her own evil goal, but Hex definately had it coming.
** [[spoiler:Sucking out Adwagia's soul for her DealWithTheDevil. While her other victims were innocent and didn't deserve it, he certainly did.]]
** The end of "Couples Retreat". Charmcaster is good with this trope.
* LittleMissBadass: In the original series.
* NotSoHarmlessVillain: Though it wouldn't seem like it given many of her past performances, [[spoiler:she manages to rack up a body count only the Highbreed and Vilgax have managed to exceed, and they have entire armies. She even killed the heroes, something no other villain has managed. The body count was only temporary, as all her victims get brought back from the dead shortly afterward, but that hardly detracts from the fact that she pulled it off.]]
* PerkyGoth: Well, sort of gothish anyway...
* TheRival: To Gwen and, to a lesser extent, to Rojo in the Negative 10.
* [[spoiler: [[HeWhoFightsMonsters She Who Fights Monsters]]: Became even worse than Adwagia to try and revive her father, something he calls her out on, resulting in a MyGodWhatHaveIDone VillainousBSOD. Thankfully, she seems to have gotten better in the next episode, trying to be a better ruler and person (though [[TookALevelInDumbass not exactly a smarter one...)]]]]
* TheStarscream: To Hex in her first appearance.
* TookALevelInDumbass: Seems to have happened to her as of ''Ultimate Alien.' In "Couple's Retreat", she's acting like TheDitz. [[spoiler: Granted, she does have the motive of wanting to fill her now-empty life with ANYTHING, even a giddy, girlish love for Darkstar, but still....]]
* TookALevelInJerkass: She wasn't nice in the original, but she's much bitchier in ''Alien Force'', especially to her golem minions.
* TookALevelInKindness: In "Where the Magic Happens" (and again in "Couples Retreat", following an [[TookALevelInJerkass extreme reset.]])
* [[spoiler:VillainousBSOD[=/=]HeelRealization[=/=]MyGodWhatHaveIDone: After she makes a DealWithTheDevil to revive her father by sacrificing all the souls in her home world, he tells her she's become SheWhoFightsMonsters and he doesn't ''want'' to be revived at the cost of some many other lives, which makes her cry as she realizes he's right. He breaks the deal, undoing everything, leaving Charmcaster completely crushed, the one thing she'd spent her entire life trying to obtain now forever out of her reach.]]
* WhiteHairedPrettyGirl
* [[spoiler:YouKilledMyFather: Says this to Adwagia.]]

!The Forever Knights

* AFatherToHisMen: Sir Cyrus, leader of the fourth Forever Knights faction, is extremely protective of his men.
* AncientConspiracy: A ''very'' complex one. One faction believes the conspiracy is to kill an Alien Dragon, another thinks its to use alien tech to conquer the world, and ''yet another'' thinks its to follow the path of "The First Knight" who founded them.
* BigBad: The Forever King; Driscoll, who was Forever King in the original series, is half the BigBad of the fourth season (Vilgax being the other half through the "Secret of the Omnitrix" three-episode movie.) and Old George for season 2 of Ultimate Alien.
* TheDragon: Enoch in the original series.
** Driscoll to Old George in Ultimate Alien.
* EnemyCivilWar: To date there are at least four Forever Knight factions, all of which think of the others as frauds. Each has their own Forever King, in order of appearence: Driscoll, Patrick, Urian, and Cyrus. This was lampshaded in one episode where Ben and company had to ask which faction the present group they were facing were with. Turns out they were with the fourth faction they hadn't met yet.
** Recently Old George, said First Forever Knight, returned and untied all four factions.
* EvilCounterpart: To the Plumbers, especially in the original series.
* FacelessMooks: [[ExaggeratedTrope Exaggerated]] in "Reflected Glory" when we see Knight with his helmet on, while brushing his teeth.
* FantasticRacism: Quite literally their mission statement; its just after Old George left last, they sorta drifted off onto other goals. Until he returned.
* FromNobodyToNightmare: Driscoll started out as just a veteran Plumber, but after being outed as someone using alien technology for his own selfish reason, joined the Forever Knights, then managed to work up the ranks, becoming the Forever ''King''.
* LetsGetDangerous: Thanks to Old George, they've gone from four splintered and laughable factions to a deadly force with PoweredArmor forcing aliens to either leave the planet or die, to the point where Ben [[spoiler:has to threaten to kill every last one of them to get them to retreat.]]
* LotusEaterMachine: Enoch put Ben into one, and then was trapped in it himself, the first series trivia pop-ups [[AllThereInTheManual say that Enoch would be in that Lotus Eater Machine for years, he did recover, though]].
* NobleDemon: Enoch on occasion, particularly the "Ben 10" video game in which he tries to stop Vilgax and save the world, though using [[WellIntentionedExtremist extreme measures]] to do so.
** The ''Ultimate Alien'' groups also have traits of this, teaming up with Ben and company on occasion.
* PoweredArmor
* PunchClockVillain: Some of them; one is even shown playing a MMORPG on his off time.
* SchizoTech: One suit was from the ancient Aztecs.
* YouHaveFailedMe: The Forever King Driscoll leaves Enoch trapped in virtual reality for failing him too many times.
** Subverted with Old George towards Driscoll.


!Sir George

* AntiVillain: [[SlidingScaleOfAntiVillains Type III]]
* BadassGrandpa: Before regaining his youth.
* BlondesAreEvil: With his youth restored.
* FallenHero: Supposedly, as his past self seemed rather heroic in his actions.
* [[spoiler:FamilyUnfriendlyDeath: Diagon strikes him with lightning and electrocutes him to ''ash''.]]
* FantasticRacism: If it isn't a pureblooded earth native, he wants it offworld or dead.
* [[spoiler:HeelFaceTurn]]
* {{Hypocrite}}: Doesn't like aliens living on his planet, even if they're just average people that do no harm. His legend was created when [[spoiler: an alien gave him the most powerful weapon ever created-that ''he'' created-without which George could never have beaten Diagon]].
* ImmortalityImmorality: Averted. Despite living for so long George holds tight to his ethics and founded an order to defend Earth from alien threats and Diagon in particular. If anything, [[WellIntentionedExtremist he has the]] [[KnightTemplar opposite problem]].
* ItsAllAboutMe: His goal is protecting humanity from Diagon which is noble enough in itself, but he seems to be convinced that only he can do it, cutting off the "alien" heroes and his own knights on occasion as he thinks [[TheOnlyOneAllowedToDefeatYou he's the only that can defeat Diagon]]. Of course, [[NotSoDifferent Ben feels the same way]].
* [[spoiler:KilledOffForReal: by Diagon.]]
* KnightOfCerebus: Responsible for making the Forever Knights formidable threats.
* KnightTemplar: IncrediblyLamePun noted on both counts.
* NobleDemon: Despite being a xenophobic KnightTemplar, he actually does have a sense of morals and honor.
* NotSoDifferent[=/=]ShadowArchetype: To Ben. Both are humans who [[spoiler: use an AmplifierArtifact created by Azmuth]], have similar issues with trust from those they protect and possess rather high opinions of themselves. The key difference is that Ben doesn't see any difference between humans and aliens while George is a champion for humanity only. The similarities between the two even cause Ben to [[spoiler: allow George the chance to take on Diagon despite Azmuth's orders - but when he fails, Ben says he gets the sword of Ascanlon to finish the job]].
* ReallySevenHundredYearsOld: [[spoiler: He was a Roman soldier in his first lifetime.]]
** BeethovenWasAnAlienSpy: [[spoiler: And he is the same person the the tale Literature/SaintGeorgeAndTheDragon speaks of.]]
* {{Telepathy}}: According to WordOfGod.
* WellIntentionedExtremist: He really does want to protect humanity-whatever the cost.

!Zs'Skayr/Ghostfreak
-> Voiced by SteveBlum (Original Series), JeffBennett (Alien Force)

* AllThereInTheManual: His name was revealed through a trivia pop-up. In-series, everyone always referred to him as Ghostfreak.
* BadBoss: when Dr Vicktor slightly questions the reason for pursuing Ben, Zs'Skayr beats the crap out of him before explaining him that Ben shouldn't be underestimated.
* BigBad: Original series, season three (though it was unknown until the finale).
* TheChessmaster: is revealed to have put a ThanatosGambit intended to resurrect him that serves as the main plot to season 3.
* EnemyWithout
* EvilerThanThou: with Vilgax in ''Ghost Town''. The [[CoolVersusAwesome fight between them]] counts as a CrowningMomentOfAwesome.
* FamilyUnfriendlyDeath: He is exposed to sunlight and bursts into flames, burning to ashes. This happens ''twice''!
* HijackedByGanon: Dr Vicktor, the Yenaldooshi and the Mummy were all three revealed to be working for him.
* HiveMind: his conciousness works that way, to the point it can survive even in the smallest sample of his DNA. He uses it both to keep surviving and to create an army of Ectonurite minions under his control in "Ghost Town".
* ManipulativeBastard
* OurGhostsAreDifferent
* SkullForAHead: a skull turned upside down with a single eye and fangs, but still a skull.
* StayingAlive: Well, he ''is'' a ghost-like alien.
* WeakenedByTheLight: Which is why he wanted Ben's body.
* WhatHappenedToTheMouse: The Zs'Skayr we know is a clone of the original resulting from his DNA being added to the Omnitrix. After having his DNA sampled, nothing is mentioned as to what became of the real Zs'Skayr.

!Simian
-> Voiced by DiedrichBader

* ConMan
* EvenEvilHasStandards: He draws the line at having his fellow Arachnichimps being possessed by Xenocytes.
* ItsAllAboutMe: He only looks to benefit himself... most of the time.
* {{Jerkass}}
** HiddenHeartOfGold
* MultiArmedAndDangerous

!Sunder the Retriever
* AnAxeToGrind: his signature weapon is an axe.
* BountyHunter
* GoodScarsEvilScars: he has a large scar on his left eye.
* RedEyesTakeWarning
* ShoutOut: He rides something similar to [[Comicbook/SpiderMan The Goblin Glider]].
** What form did Ben take when they first fought? Yeah, Spidermonkey.

!Diagon
-> Voiced by JohnDiMaggio

* AGodIAm: he doesn't explicilty stats it, but he could as well say so. Of course, considering what [[EldritchAbomination he is]]...
* AndShowItToYou: Old George tore out his heart. This didn't kill him and he had to be turned into SealedEvilInACan.
* BigBad
** BiggerBad: Was the dragon the Forever Knights were founded to fight, making everything connected to them his fault.
* {{Cthulhumanoid}}
* DimensionLord
* EldritchAbomination: He's not named after a Great Old One for nothing.
** Just ''looking'' at it in a PensieveFlashback causes Ben, Gwen and Kevin to freak out. Consider what they fight on a daily basis and that says a lot about how horrible it is.
* EvilerThanThou: [[spoiler:Finds out too late that Vilgax was this to him.]]
* HealingFactor: at several points in ''The Ultimate Enemy'', his injuries heal as soon as he gets them.
* [[spoiler:KilledOffForReal: After being converted by Vilgax into pure energy and absorbed by Ben into Ascalon.]]
* MultiversalConqueror: He had taken over a hundred dimensions by the time he fought George, according to Azmuth.
* [[spoiler:OurDragonsAreDifferent: He is depicted as one by The Forever Knights]]
* [[spoiler:OutGambitted: Though he was the one pulling Vilgax's strings, only to find out too late it was the other way around the entire time.]]
* RealityWarper: he displays abilities such as creating an acid rain, size-shifting, [[spoiler:stripping George of his immortality]]
* SealedEvilInACan: Was imprisoned in his universe by Old George. Justified as ''cutting his heart out'' wasn't enough to kill it so there weren't many other options.So now he's trapped in Azmuth's sword.
** It's been confirmed on the credits of "The Enemy of My Frenemy" that [[spoiler: HE was the "Old One" who was willing to accept 600,000 souls.]]
** [[spoiler:Diagon may have ultimately sealed inside [[CoolSword Ascalon]] when Ben uses to to steal his power from Vilgax, if he wasn't killed by Vilgax absorbing him.]]
* WorldWreckingWave: When he comes close to being freed, one of these is set off, turning every unprotected human on Earth into his minions.

!Eon

* BigBad: Of "Race Against Time".
* [[spoiler:DeaderThanDead: In the end, he's ''erased from time''.]]
* {{Expy}}: his movie design was said to be partially based on Darth Vader by one of the producers.
* HesBack: He reappears in the actual series in "Ben 10,000 Returns".
* OneShotCharacter: For Ben to use with the Omnitrix, since he's not in it anymore. Justified in that "Race Against Time" ''was'' canon, but not with the main timeline.
* ShoutOut: His plan in "Ben 10,000 Returns" is rather simular to [[spoiler:the BigBad in ''Film/TheOne''. Wiping out and absorbing all alternate versions of themselves.]]
* TimeMaster: Works on humans [[spoiler:and aliens.]]
* TomatoInTheMirror: He and his minions are all revealed to be [[spoiler:Ben Tennyson, of an alternate timeline. Though since the Eon from the movie intended to turn Ben into a new Eon, we can't be sure he's the ''original'' Eon]].

!The Highbreed

* [[AllYourPowersCombined All Your DNA Combined: After Ben recalibrates their genetic makeup, this is what happens.]]
* AlwaysChaoticEvil: [[spoiler:subverted; the only reason they are evil is because of their racist ideology. Reinrassic III gradually becomes nicer following his EnemyMine with Ben, and, after he convinced his comrads to give up the whole OmnicidalManiac way, they are no longer portrayed as evil.]]
* BigBad: ''Alien Force'''s first two seasons.
* TheBlank: their face possess no visible features other than several red eyes that don't even move, making you wonder if they even are actual eyes.
* [[spoiler:DyingRace: the real reason behind their invasion; they wanted to destroy the universe because they were too proud and didn't wanted to die alone.]]
* [[spoiler:EasilyThwartedAlienInvasion: played with; the heroes are unable to stop their invasion using force, and Ben has to solve the conflict peacefully by solving their DyingRace problem so they won't feel the need to destroy the universe anymore.]]
* FantasticRacism: to the extreme; when one of them got bitten by Humongousaur, he claimed to have been infected, and that he had to leave and disinfect the whole zone. By killing everything around of course.
* [[spoiler:HeelFaceTurn]]
* {{Irony}}: They wished to wipe out all species save their own due to their inevitable extinction, [[spoiler:but now they have become amalgamated with those very races.]]
* KnightOfCerebus: to the saga as a whole; the beginning of their story arc in the first two seasons of Alien Force marked the point where the saga went into a DarkerAndEdgier tone, and they were truly menacing and oppressing villains. Similarly, after the end of their story arc, Alien Force suddenly changed tone to get more humorous.
* MasterRace
* OmnicidalManiac: Planned to wipe out all sentient life in the universe.
* ScaryDogmaticAliens: the "Aliens Are Nazis" type.

!The Hive

* AuthorityEqualsAsskicking: The queen is much larger than the drones and far stronger.
* BodyDouble: In "Revenge Of The Swarm", it's revealed the queen Ben already killed was a fake and the real queen was [[spoiler: hiding inside Elena.]]
* BigBad: Of the second live action movie.
* CassandraTruth: Victor Validus tried to warn the Plumbers the Hive were preparing to attack but no one believed him until the invasion was already started.
* HiveQueen: The queen of the hive serves this role. However, she's also the only one able to reproduce like a real insect queen and killing her takes the Hive with her.
* IAmLegion: The Hive's hosts refer to themselves as 'we', even the Queen's host despite the fact she refers to herself in the singular.
* {{Nanomachines}}: They're techno-organic nanite chips.
* PuppeteerParasite: Anyone infected by the Hive is put under their control and becomes 'drones' for the queen to control.
* ShockAndAwe: The Hive Queen and Nanomech are capable of this.
* WeCanRuleTogether: During their fights with Ben, both queens try to convince Ben to join them as their king.
* [[spoiler:{{Yandere}}: toward Ben, after Elena became one with them.]]
* YouWillBeAssimilated: Their MO is to infect and take over everyone on the entire planet.

!Michael "Mike" Morningstar (Darkstar)
-> Voiced by WilWheaton

* [[spoiler: AnticlimaxBoss: In the first season finale of "Ultimate Alien".]]
* BlondGuysAreEvil: Not blonde anymore though [[spoiler: but he later regains his original appearence]].
* ChronicBackstabbingDisorder: EVERY time he shows up he ends up double-crossing someone somehow. Comes back to bite him once Ben gets GenreSavvy to him.
* DarkIsEvil: As Darkstar
* DoesThisRemindYouOfAnything: His habit of draining energy for girls is played up suspiciously to be like [[RapeIsASpecialKindOfEvil rape.]]
* EnemyMine: Helps Ben and his friends against the Highbreed invasion, teams up with Kevin to gain an artifact only to betray him afterwards, and [[spoiler: helps out again in Ultimate Alien's first season finale, only to make a failed backstabbing attempt in the end.]]
* EnergyAbsorption
* EvilCounterpart: To Gwen (similar powers) and Kevin (similar personality).
* LightIsNotGood: As Mike Morningstar, who not only was beautiful and blonde, but his powers were mostly represented by golden/yellow light. As Darkstar, his powers now are obviously [[DarkIsEvil dark energy]], but [[spoiler:he once almost regained his original appearence, and presumably his powers]].
* LightningBruiser: Morning Star
** MightyGlacier: Darkstar
* {{Jerkass}}
* ManipulativeBastard: To Gwen in his debut appearance, and later to Kevin, and later to [[spoiler: Charmcaster.]]
** [[spoiler: Subverted in "Aboslute Power", in which the heroes are completely prepared for his manipulation and inevitable double-cross.]]
* NamesToRunAwayFromReallyFast: "Morningstar." Sometimes used as a divine title for Jesus. More commonly used as the translation of "Lucifer" into English.
* NotSoDifferent: Points out in ''Ultimate Alien'' that he and insane Kevin are the same. Kevin confirms this later by calling Gwen "Lovely Gwen", Darkstar's name for her.
* OutGambitted: No one ever suspected he would betray Ben and company after he helped turn Kevin sane again. [[GenreSavvy Oh wait, yes they did]].
* TheSociopath: He has no empathy for anyone but himself.
* StevenUlyssesPerhero: Michael ''[[{{Satan}} Morningstar]]''? [[SarcasmMode Yeah, I see why Gwen believed he was]] MostDefinitelyNotAVillain.
** Sort of an odd example of ViewersAreMorons, where they're expecting someone older or smarter (like Gwen is supposed to be) in the PeripheryDemographic to catch it, but to a little kid, he has a good-guy-sounding name.
* ThatManIsDead: "Michael Morningstar no longer exists. Now I am Darkstar!"

!Sixsix and Sevenseven

* AllThereInTheManual: Before the second series, the pop-ups in the first series confirmed Sevenseven's existence. They're also brothers (with Sevenseven obviously being the elder).
* BountyHunter
* DeeBradleyBaker
* SuspiciouslySimilarSubstitute: Sevenseven.
* TheUnintelligible
* UpToEleven: Sevenseven is basically this to Sixsix.
* WhatHappenedToTheMouse: It's presumed Sixsix was sent back to Incarcecon after "Secret of the Omnitrix"

!Albedo
-> Voiced by YuriLowenthal

* AndIMustScream: Ends up in a nightmare caused by a Cassiopeian dream eater.
* EvilAlbino
* EvilCounterpart ''and'' EvilTwin: Thanks to weird connections between the Omnitrix systems, his new default form is a PaletteSwap of Ben.
* FailureIsTheOnlyOption: DoubleSubverted. He finally has the ability to turn back into his original form... only it's temporary.
* IneffectualSympatheticVillain: You can't help but feel bad for the guy, stuck in a human body that causes him no end of grief.
** "Double Or Nothing" all but spells this out: by only wanting to turn back to normal, he's (d)evolved into a {{Harmless|Villain}} AntiVillain.
* HoistByHisOwnPetard: Gets himself attached to a Cassiopeia dream eater he meant for Ben.
* InsufferableGenius: As a Galvan he's extremely intelligent and helped build the Omnitrix so he does have smarts, but he insults and demeans everyone else from Ben to Azmuth to ''Vilgax'' as he believes himself to be the most brilliant being in the universe. Not surprisingly this comes back to bite him in the ass repeatedly, especially in the series finale of ''Alien Force''.
* LargeHam: "BRING ME CHILI FRIIIIIIIIIIIIIIES!!!"
* MeaningfulName: "Albedo" refers to the reflection in physics and the state of purification in alchemy.
* PutOnABus: Disappeared from ''[[WesternAnimation/Ben10AlienForce Alien Force]]'s "[[GrandFinale The Final Battle]]" without a trace, only to return halfway through Ultimate Alien.
* ShapeShifterModeLock: Zig-zagged, he can shift back into his Galvan form but he always turns back into Ben's form in the end.
* TedBaxter: He's the greatest scientific mind in the universe! Or so he says. Yet his versions of the Omnitrix and Ultimatrix have glaring design flaws that nearly prove fatal to himself and others on several occasions. Naturally, [[NeverMyFault he blames this on Azmuth and Ben instead of owning up to his own mistakes]].
* WhiteHairedPrettyBoy

!Ragnarok

* ArchEnemy: To Kevin for the one episode he was in.
* NamesToRunAwayFromReallyFast
* OmnicidalManiac: His job is destroying suns and killing solar systems.
* SaveTheVillain: Averted. Kevin let him ''fall into the sun!''

!Aggregor
-> Voiced by JohnDiMaggio

* [[spoiler: AGodIAm: His ultimate plan was to absorb the powers of a Alien X and reshape the universe to his whim.]]
* AllYourPowersCombined: Intends to permanently assimilate [[ElementalPowers Fire, Water, Earth, Wind, and Electric]] powers from a quintet of aliens from the Andromeda Galaxy.
* [[AntiMagic Anti-Mana]]: Courtesy of absorbing Galapagus.
* {{Badass}}: he is by far one of the most competent villains in the show, possibly in the saga.
* BadassLongcoat
* BadassLongHair
* BigBad: For the first season of ''Ultimate Alien'' [[spoiler: until he ends up [[HijackedByGanon hijacked by Kevin 11.]]]]
* BodyHorror: His first use of Galapegus' powers involves multiple ''vents opening on his body''. YMMV on how it compares to [[spoiler:Ultimate Aggregor.]]
* [[spoiler: BroughtDownToNormal: Thanks to Kevin absorbing his powers. It's assumed he can still absorb matter and energy since that's considered "normal" for Osmosians.]]
* DangerouslyGenreSavvy: one of the main reason he was so unstoppable for most of the season.
* EvilCounterpart: To Kevin. As noted below, he is very similar in role and personality to Kevin in the first show, as well as being of the same species, with the same powers and love of absorbing energy. Kevin seems to be aware of how similar they are, and has apparently taken this to heart given how intense he is about stopping him.
* {{Expy}}: Aggregor is basically Kevin if he ''didn't'' reform: sadistic, merciless, and with the power to absorb energy, complete with his body mutating to accomodate the stolen alien power.
* [[spoiler: FakeBoss: Kevin ends up becoming the final enemy to face in ''Ultimate Alien's'' first season.]]
* HiddenAgendaVillain: His true goal, to reshape the universe the way he wants, was kept hidden until his last appearance.
* KickTheSonOfABitch: Stealing the power of fellow CompleteMonster Addwagia in "Where The Magic Happens".
* MeaningfulName: He aggregates (collects) the powers of other aliens.
* MegaManning: His base power allows him to steal the abilities, and apparently life force, of whoever he touches. However, he can only use the stolen power at a tenth of its original strength, and it wears off. He's built a machine to subvert this, fully and permanently absorbing the power of the five aliens he's hunting at the cost of killing them.
* [[spoiler: PoweredByAForsakenChild]]: In "The Forge of Creation" [[spoiler: he goes after a baby Alien X with the goal of stealing its RealityWarper powers]].
* RubberForeheadAlien: In his default form he looks essentially like a human with a row of spikes on his head.
* TheSociopath
* WhatHappenedToTheMouse: WordOfGod says he's currently incarcerated.

!Will Harangue
-> Voiced by JohnDiMaggio

* {{Expy}}: He's [[SpiderMan J Jonah Jameson]] mixed with [[XMen Senator Kelly]] as a TV pundit.
* {{Jerkass}}: There are many other names for him, though ''nothing'' seems strong enough.
* KarmaHoudini: Pretty much got off scot-free for his actions in "Computer Games", save for the billions he spent on the robot. [[AndThatsTerrible And his car]].
* MeaningfulName[=/=]PunnyName
* TheScrappy: Given [[{{Jerkass}} his character]], this is definitely [[InvokedTrope invoked]].
* StrawmanPolitical: Though a blender of several political pundits (as one message board noted: he's like the worst of Bill O'Reily, Keith Olbermann, Glenn Beck, Al Franken, and even Stephen Colbert mixed in a blender.)
** ObfuscatingStupidity: Alot of the StrawmanPolitical pundit stuff is for show; behind the scenes, he's pretty sinister.
* VillainWithGoodPublicity: More like ''Incredible''. Despite ''many'' problems in his smear campaign against Ben, he not only manages to somehow avoid being arrested by the feds, but also seems to ''still have enough of a following to keep his show.''

!Carl Nesmith/Captain Nemesis/Overlord
* BrokenPedestal: Ben used to idolize him before finding out how much of a jerk he had become.
* [[spoiler:EvenEvilHasLovedOnes: his feelings for Jennifer Nocturne were apparently sincere, or at least became so.]]
* {{Expy}}: he wears similarities with both Warp from Comicbook/TeenTitans and, to a minor extent, IronMan.
* GreenEyedMonster: the major reason for him turning evil was because of his jealousy toward Ben. Ironically, Ben didn't mean to ruin his reputation and [[BrokenPedestal was actually a big fan of him before he turned evil]].
* FallenHero: he started out as a superhero, but ended up trying to cause fake kidnapping in order to get popular again, and eventually turned into a criminal due to his jealousy toward Ben. Both Ben and his Agent hinted he had been an actually great hero before.
* [[spoiler:PetTheDog: surrendered so his accomplice Jennifer Nocturne could get medical attention.]]
* [[spoiler:ShootTheDog: he was one of the few villains in the show to be explicitly hinted to have killed human beings. At one point, he even killed an innocent driver just to steal his car.]]
* PoweredArmor
* ThatManIsDead: "Captain Nemesis is dead! Now, call me ''Overlord''!"

!Zombozo
-> Voiced by John Kassir (Original Series), JohnDiMaggio (Ultimate Alien, Omniverse)

* AxeCrazy: [[spoiler:in Ultimate Alien, he tried to kill Ben's mother in a very sadistic way while Gwen was watching. And it's clearly implied he buried someone at the beginning of the same episode]]
* {{Expy}}: In the first series, some have noted him to be very similar to that of [[{{IT}} Pennywise the clown]]. He's much more like TheJoker in ''UltimateAlien''
* MindRape: inflicted this to Ben in his first appearance by taking advantage on Ben's [[WhyDidItHaveToBeSnakes fear of clowns]]. [[spoiler:Ben then payed him back using Ghostfreak.]]
* MonsterClown
* NinjaPirateZombieRobot: He is, as some plot descriptions on websites gave him: A Zombie Vampire Clown.
* OurVampiresAreDifferent: in his first appearance, he fed of people's happyness. The result when he got all of it wasn't pretty.
* SameCharacterButDifferent: In the first series, he has a very supernatural edge to him. ''Ultimate Alien'' made him out to be an incredibly Joker-esque character with none of the powers he demonstrated in the first series, though he still has the same overall personality.
* SlasherSmile

!Serpent
-> Voiced by DeeBradleyBaker

* {{Expy}}: he bears similarities with King Cobra from the MarvelUniverse.
* NotSoHarmlessVillain: in his first two appearance, he was handled by Ben so easily it was almost ridiculous. Then, when he appeared for the third time, he proved to be DangerouslyGenreSavvy enough to set a trap instead of fighting Ben head on, and almost succeeded in killing him.
* SmugSnake: as fitting for his snake-like appearance.
* SnakePeople
* SnakeTalk
* TheWorfEffect: he is infamous for this; in his very first appearance, he was able to handle Gwen and Kevin of his own... then Ben arrived and [[CurbStompBattle defeated him in a few seconds]].

! The Inkursians
* AliensAreBastards: let's just say that you might wonder what's wrong with this species' sense of ethic. To give you an idea, one of their emperor was ready to blow up Earth because his daughter was missing. [[spoiler:Then his daughter comes back and overthrows him, but still wanna blow up Earth ForTheEvulz. And when the emperor comes back to power, he ''congratulates'' her for overthrowing him.]]
* BloodKnight: according to "Con of Rath", they ''love'' war, to the point they attacked Ben's team just because they were carrying a peace offering.
* ChronicBackstabbingDisorder: this is apparently considered a standard procedure in their politic system.
* [[spoiler:FreudianExcuse: according to Azmuth, it was following the destruction of their planet due to the Astallion sword that they ended up as the space pirates they are now.]]
* WeaksauceWeakness: methane cause them to uncontrollably suffocate. Since Swampfire constantly produce methane, he can as such defeat them by his mere odour.

! The Vreedle Brothers
-> Octagon voiced by JohnDiMaggio
-> Rhomboid voiced by RobPaulsen

* {{BFG}}: often relie on this as their weapons.
* BewareTheSillyOnes: as hard as it is to admit, they can be pretty dangerous due to their massive weaponry. Though if you think about it, it's precisely the fact they are ''truly'' silly that makes them dangerous...
* BountyHunter
* DumbMuscle: both of them, especially Rhomboid.
* EvenBadMenLoveTheirMamas: They really respect their mother, Ma Vreedle. Too bad she considers them as failure (not that we can object her...).
* HeelFaceRevolvingDoor: In their first appearance in Ultimate Alien, they're attending the academy to become Plumbers. However, the next episode they're in they are back to being thugs. Gwen scoulds them for this, and they return to Plumbers shortly after.
* KilledOffForReal: some of them. Of course, since [[MesACrowd there are an army of them anyway]], that doesn't really count...
* LeeroyJenkins: they basically don't know how to solve any problem without blowing up things.
* MesACrowd: it's revealed in Con of Rath that there are actually a whole army of Vreedle Brothers, since they are actually clones created by their parents through a kit.
* OneBadMother: Ma Vreedle.
* StupidEvil: they take that trope UpToEleven.
* ThoseTwoBadGuys
* TooDumbToLive: a ridiculously extreme exemple when they shoot a fusion grenade at Kevin. In a space station. When Argit points out that will not just kill Kevin, but ''everyone on the station'', including them, Octagon admits he "didn't consider this".

!Khyber
-> Voiced by DavidKaye

An hunter who will apparently serves as the main villain in season 1 of ''WesternAnimation/Ben10Omniverse''.

* BigBad: Of Omniverse (at least season 1, it seems).
* EgomaniacHunter: Considers Ben "Worthy prey" and has the head of another alien hoisted on his wall.
* EvilCounterpart: to Ben, to an extent; he possesses an artifact described by the producers as an kind of "Evil Omnitrix" that he can use to convert his pet in various creatures that are all predators to Ben's aliens.
* EvilSoundsDeep
* {{Expy}}: Not in his design, but his ship, mentality and obsession with hunt seem to have a lot in common with the Franchise/{{Predator}}.
* HuntingTheMostDangerousGame
* SpikesOfVillainy

[[/folder]]

[[folder:Allies]]

!Julie Yamamoto

* BobHaircut
* BrownEyes
* WomenAreWiser
* DerailingLoveInterests: Julie has become much less nice since the start of ''Ultimate Alien''. Some of this is having to deal with Ben being famous (it was very justified in the episode w/ Captain Nemesis), but she's showing new traits such as being overly competitive and short-tempered that weren't originally present, possibly as a misguided attempt at giving her more flaws.
** She joined what was effectively a cult in "Flame Keepers Circle." She thought it was a corporation that was trying to improve people's lives by introducing alien tech at a faster rate than the Plumbers wanted (despite Kevin and Ben both warning her that such an act typically destabilized planets). It was really a bunch of crazy people worshiping Vilgax, and it was ridiculously clear too, but she grabbed the IdiotBall firmly until it was beyond obvious she was wrong.
*** And yet in the next episode they [[spoiler: brought back Elena, crazier than ever, and had her impersonate Julie as a "perfect girlfriend" for Ben]] as a sort of TakeThat to shippers who hate Julie for reasons like her not accommodating Ben enough.
* [[ABoyAndHisX A Girl and Her Shapeshifting Weapon/Pet Alien]]
* KidWithTheRemoteControl: Ship.
* LoveInterest: To Ben.
* MagicSkirt
* PluckyGirl
* ShallowLoveInterest: Initially appeared out of the blue; [[CharacterDevelopment she gets]] [[RescuedFromTheScrappyHeap better over time]].
* SixthRanger
* TookALevelInBadass: Getting Ship helped with this, as he can turn into PoweredArmor for her. She's also quite adept with certain weapons.

!Ship

* BigDamnGunship: several cases. "Eye of the Beholder" had an interesting inversion where he ''left'' Julie on Earth to save someone else.
* CoolShip: Some ''serious'' ShapeshifterBaggage involved here.
* EvilDetectingDog: Knew when [[spoiler: Julie was being impersonated by Elena, who was using the Hive chips]].
* MeaningfulName: Not just his gunship form, but [[FridgeBrilliance he's proven integral to Ben and Julie's relationship on occasion.]]
* MundaneUtility: He acts as a ''tennis ball launcher'' one time.
* PokemonSpeak
* PoweredArmor
* RidiculouslyCuteCritter
* TeamPet

!Azmuth
-> Voiced by Robert David Hall (Original Series, Destroy All Aliens), JeffBennett (Alien Force and Ultimate Alien)

* CynicalMentor
* FigureItOutYourself: "Don't you want to figure it out on your own, like a true hero would?"
* HeelRealization: He realizes it's just stupid to blow up the universe when the Omnitrix is near self-destruction.
* InsufferableGenius
* NotSoDifferent: He's immature, selfish, cracks jokes at inopportune times, but when it comes down to it, he can be helpful... sort of like Ben. This is all the more obvious when he says that he likes Ben for saying that he didn't want to figure out how to work the Omnitrix better (or, more specifically, allowing Ben to change forms at will within alien form).
* SameCharacterButDifferent: Was a lot more sarcastic and cynical when we first see him in ''Secret of the Omnitrix'', but is more stoic and serious (though retaining a sense of humor) by the time of ''Alien Force''. Justified in that there was a five year TimeSkip in-between appearances.
* SinkOrSwimMentor
* TheSpock
* TheWatcher

!Professor Paradox

* TheAgeless: Due to existing outside of time, he can't age and apparently also doesn't need to eat or sleep. This also makes him immune to time manipulation to some degree (he can't be aged into dust or anything like that, but he still feels it to some degree).
* BadassBoast: Tells Eon that if he goes through with his plan, no force in all of time will be able to protect him from Paradox.
* BoredWithInsanity: In his own words.
* CallForward: WordOfGod said that in ''Race Against Time'' (a movie that's otherwise questionably canonical), Paradox guarded the Hands of Armageddon from Eon for several years until Ben stopped him.
** This is finally revealed in Ben 10,000 Returns. [[spoiler: The movie was actually part of 'cross-time' and thus Paradox guarded that alternate timeline's Hands of Armageddon]]
* {{Expy}}[=/=]{{Homage}}: [[Series/DoctorWho The Doctor]], especially [[TheNthDoctor the tenth incarnation]].
** May also be one of Sam Beckett from ''QuantumLeap'': scientist who gets caught in TimeTravel experiment, vanishes and appears in a blue-white light and tries to SetRightWhatOnceWentWrong.
* TheFogOfAges: He calls himself 'Paradox' because he can't remember what his real name is
* GoMadFromTheIsolation: Spent nearly ''ten thousand years'' floating randomly through time. But eventually, he got BoredWithInsanity and went sane again.
* HeroOfAnotherStory: Is apparently constantly on adventures of his own and the first time he appears, its stated he's already saved the world ''hundreds'' of times.
* HeyItsThatVoice: [[Series/{{NCIS}} Ducky]] can time travel!
* OffscreenTeleportation: Has this ability due to 'finding shortcuts' in time. Though he's also very capable of onscreen teleportation.
* PersonaNonGrata: Is banned from ineracting with Alien X, [[NoodleIncident for reasons unknown]].
** May have something to do with hiding the Forge of Creation, which is a NoodleIncident in itself.
* ReallySevenHundredYearsOld
* SetRightWhatOnceWentWrong: His job for the past several hundred years.
* SinkOrSwimMentor: In the sense that he can't outright interfere. He does provide hints and warnings that help guide Ben and the others' actions.
* TemporalParadox: Once a theory of his, now the frequent results of his actions.
* TimeAbyss: Originally from TheFifties, he was sent back to the beginning of time and went on from there.
* TimeDissonance
* TimeMaster
* TimePolice: Self-appointed
* TimeTravelTenseTrouble
* TricksterMentor

!Plumber's Kids

* BrickJoke: Pierce is the only one whose appearance doesn't come from any Omnitrix alien. [[spoiler:Turns out he's from Argit's race (Argit demonstraded a shooting-quill ability in "Andreas' Fault").]]
* DroppedABridgeOnHim: [[spoiler:Pierce in "The Purge".]]
* {{Expy}}: Manny, Helen and Alan are half-Tetramand (Fourarms), half-Kineceleran ([=XLR8=]), and half-Pyronite (Heatblast) respectively. Pierce's powers are also reminiscent of [[XMenEvolution a certain needled X-Man]].
* FiveManBand:
** TheHero: Pierce
** TheLancer: Helen
** TheSmartGuy: Cooper
** TheBigGuy: Manny
** TheChick: Alan
* GettingCrapPastTheRadar/ PunnyName: Helen Wheels.
* HalfHumanHybrid: The Expies shown above are half-human.
* HeIsAllGrownUp: Cooper, in Ultimate Alien, [[MrFanservice grew about two feet and went up to about a nine.]]
* HeyItsThatVoice: Manny is [[WesternAnimation/TeenTitans Cyborg]].
* HopelessSuitor: Cooper, for Gwen.
* TheOtherDarrin: Cooper has been voiced by Cathy Cavadini, Corey Padnos, and Chris Pratt, though given his gradual physical changes as he ages, [[JustifiedTrope this makes sense]].
* SacrificialLion: [[spoiler:Pierce's cold blooded murder by the Forever Knights showed just how merciless and dangerous they'd become.]]
* TheSmurfettePrinciple: Helen is the only female in the team.
* StockSuperpowers
** PlayingWithFire: Alan
** SuperSpeed: Helen
** SuperStrength: Manny
** {{Technopath}}: Cooper
* TokenHuman: Cooper, if only in appearance.
* TookALevelInBadass: Cooper, in addition to a level in good looks.
* WhatCouldHaveBeen: Cooper would have held Kevin's place after the TimeSkip, but according to Dwayne [=McDuffie=], it was Murakami who had Kevin become the new teammate instead.

!Tetrax

* TheAtoner: He was the one responsible for giving Vilgax the crystal that inevitably became Vilgax's tool for destroying Tetrax's planet.
* {{Badass}}
* BountyHunter: Initially, he also worked for Vilgax, but, he's decided to fight against him for what he did to his home planet.
* HoverBoard: Also his production name.

!Jimmy Jones
-> Voiced by ScottMenville

* ActionSurvivor: particularly in "The Big Story".
* AlliterativeName
* BadassNormal: Reveals himself to be one in "The Big Story", where he singlehandedly saves Ben, Gwen, and Kevin...multiple times.
* BigBeautifulWoman: Jimmy's ''[[HotMom mom]]'', who's appeared framed by the doorframe as if to emphasise this. [[CuteButCacophonic And then she starts yelling for him.]]
* BrokenMasquerade: Exposes Ben's identity to the world, but thought he would enjoy the fame (which he does).
* ChildProdigy: Deduced that Ben and the aliens were one and the same after years of investigating. He's ''ten''.
* {{Expy}}: of [[NotSoDifferent first-series Ben.]]
* ImYourBiggestFan
* MeaningfulName: He's named for two well-known sidekicks, ''Jimmy'' Olsen from {{Superman}} and Rick ''Jones'' from TheIncredibleHulk.
* MissionControl
* UnwittingPawn: "The Big Story" all but confirms that [[NiceJobBreakingItHero Jimmy's investigations were the very thing that got Will Harangue his big start.]]
* WideEyedIdealist


!Eunyce[[spoiler:AKA the Unitrix]]
* [[spoiler:ArtificialHuman: she is actually a Omnitrix-like device created by Azmuth to store DNA, who turned into a girl after scanning Gwen's dna.]]
* EveryoneLovesBlondes: Ben sure does.
* FriendToAllLivingThings: one of her abilities.
* LoveInterest: to Ben in her first appearance.
* TookALevelInBadass: in her first appearance, she was a naive girl who could barely stand a fight. The next time we see her, she can fight toe to toe with Arachnichimps Dnaliens.

[[/folder]]

[[folder:Others]]
!Cash and JT

* ButtMonkey: Whenever they appeared in the original series, Ben found the time to give them a mega-wedgie.
* CreepyChild: Invoked with [[EeriePaleSkinnedBrunette pale-skinned black-haired]] Cash.
* {{Guyliner}}: Cash(!)
* IneffectualSympatheticVillain: Particularly from ''Alien Force'' onwards.
* NerdGlasses: JT.
* TheReasonYouSuckSpeech: Courtesy of Ben in "The Gauntlet." After they spill a smoothie on him as a prank, he chides them for pulling the same nonsense since grade school and admits disbelief that he used to be afraid of Cash. Though JT took it in strides but Cash [[EvilIsPetty took it personally]].
* RedheadedBully: JT is ironically the Beta Guy of the two.
* SchoolyardBullyAllGrownUp: Attempted from ''Alien Force'' onwards.
* ThoseTwoGuys

!Carl and Sandra Tennyson

* AmazinglyEmbarrassingParents: Invoked. They're the stereotypical [[GranolaGirl Granola Couple]].
* CanonImmigrant: Added to the cartoon after debuting in ''Race Against Time''.
* DotingParent: Both tend to do this, but Sandra arguably takes it a bit further.
* HippieParents
* HotMom
* LockedOutOfTheLoop: [[HiddenDepths Possibly.]]
* ObfuscatingStupidity

!Argit

* DirtyCoward
* NotQuiteDead: An ''actual ability'' of his race.
* PettingZooPeople: [[AstonishinglyAppropriateAppearance A hybrid rodent of sorts.]]

!Baz-El
-> Voiced by RobPaulsen

* AsteroidsMonster: Notably spawning a ''regular character'', Ship.
* BritishAccent
* JerkWithAHeartOfGold

!The Andromeda Five
%%Tropes specific to their involvement in the Aggregor story arc as opposed to being Ben alien forms go here.

* CannotTellALie: Galapegus. But he learns.
* ComboPlatterPowers: Ra'ad throws lighting, has telepathy, enters electronic devices by ''becoming'' lightning and enters ''pretty much anything else'' by becoming liquid. [[spoiler:And bodyjacking, which Ben himself never bothered with but ''the king of Zarcovia'' can somehow channel to put his own soul in the body of Dr Viktor.]]
* DumbMuscle: Andreas.
* ElementalPowers:
** BlowYouAway: Terraspin
** DishingOutDirt: Armodrillo
** MakingASplash: Water Hazard
** PlayingWithFire: NRG
** ShockAndAwe: Ampfibian (though he ''does'' have a water form as well)
* EnergyBeing: P'andor
* FiveManBand:
** TheHero: Bivalvan (Water Hazard)
** TheLancer: P'andor (NRG)
** TheSmartGuy: Ra'ad (Ampfibian)
** TheBigGuy: Andreas (Armodrillo)
** TheHeart: Galapagus (Terraspin)
* HeroicSacrifice: [[spoiler:Andreas. Is it a subversion if ItGotWorse for him?]]
* HuskyRusskie: P'andor (but subverted since it's just the suit's appearance).
* LetsGetDangerous: Galapegus.
* MeaningfulName:
** Galapagus takes his name from the well-known Galapagos tortoise (and possibly the Galapagos Islands since they, like him, have remained uncorrupted by the outside world)
** P'andor refers the story of Pandora's Box.
** Andreas is obviously a reference to the San Andreas Fault.
* SharingABody: Rather like Ghostfreak, Ben's first use of Ra'ad leads to this temporarily.
* TokenEvilTeammate: P'andor.
* WithGreatPowerComesGreatInsanity: Technically P'andor's great insanity goes from bad to worse.

!Kwarrel

* BadassBeard
* CoolOldGuy
* MentorOccupationalHazard
* TheObiWan: to Kevin. [[spoiler:He was the one who helped him to get rid of his psychosis and original mutant form, as well as teach him how to use his new powers.]]
* PosthumousCharacter: his first and so far only appearance was in season 1 of Ultimate Alien; he actually died in the gap between the original series and Alien Force.

!Jennifer Nocturne

* CelebrityIsOverrated
* HairOfGold: [[spoiler:Now she dyed it black.]]
* HiddenDepths
* [[spoiler:ParentalNeglect: The reason why she ran away to become a celebrity.]]
* [[spoiler:SoBeautifulItsACurse]]

!Colonel Rozum
-> Voiced by JohnDiMaggio

* KnightTemplar: He imprisoned over 700 alien in Area 51 because they "might" become a threat to Earth.
* WhatTheHellHero: Max calls him out on his actions in "Prisoner Number 775 is Missing".

[[/folder]]

----

* LongHairedPrettyBoy: His hair reaches his shoulders

* TheOtherDarrin: As a kid, he had two voices: one in his first appearance, then another in his future appearances.

[[quoteright:250:http://static.tvtropes.org/pmwiki/pub/images/Ben_UltimateAlien_8498.png]]

* HeyItsThatVoice
** TaraStrong: As a kid.
** YuriLowenthal: As a teenager.
** FredTatasciore: The future Ben seen in "Ben 10,000" and "Ken 10".

* HeyItsThatVoice:
** AshleyJohnson: As a teenager.
** TaraStrong: The future Gwen(dolyn) seen in "Ben 10,000" and "Ken 10".

* Letting Their Hair Down: In the first two seasons of Ben 10: Alien Force and when wearing a plumber suit.

* MsFanservice: SHe even appears in bikinis in the [[BeachEpisode beach episodes]].

* HeyItsThatVoice: Bellicus and Serena were voiced by KevinConroy and Vicki Lewis in ''Alien Force'' and voiced by JeffBennett and TaraStrong in ''Ultimate Alien''.

* YuriLowenthal: In his initial appearance, possibly to avoid TalkingToHimself as DeeBradleyBaker also voiced Ra'ad.

* DaranNorris: Diamondhead in ''[[TheMovie Race Against Time]]''.

!! '''Fourarms''' (OS-02)

* HeyItsThatVoice: [[http://avatar.wikia.com/wiki/Bato Bato]] (from WesternAnimation/AvatarTheLastAirbender) in the original series.
** JohnDiMaggio: On 10-year-old Ben in ''Ultimate Alien''.
* LeeroyJenkins: Most notable in the first series, when ever Ben would act incredibly impulsive during a fight, chances are he'd turn into Fourarms.

* VocalEvolution: Richard [=McGonagle=] uses a deep growling voice early on in season 1 of the original series. By season 2, he uses the higher gargling tone Fourarms is known for.

* HeyItsThatVoice
** JeffBennett: ''Alien Force''
** StevenBlum: Original series.

* HeyItsThatVoice
** GreyDeLisle: In the alternate reality episode, "Gwen 10".
** SteveBlum: In the original series. However, Baker provides a dead-on impersonation in ''Ultimate Alien'' for young Ben. [[hottip:Note:He uses a different voice for teen Ben]].

* HeyItsThatVoice: In "Alien Swarm", Nanomech was voiced by Alex Winter (Yes, ''[[BillAndTed that]]'' Alex Winter), who also directed both that and "Race Against Time".

* JohnDiMaggio

* DavidKaye: His voice in ''Ben10Omniverse''. Apparently, also his voice in ''Heroes United'', as well.

* DaveWittenberg: His voice in the original series.

* TaraStrong: Basically, Upgrade was Ben's normal voice in an effect added in to make it sound digital.
** Hence, when he returned, YuriLowenthal became his voice actor.

!! '''Way Big''' (Secret of the Omnitrix [[hottip:*:Part 3, or technically OS-52]])/Ultimate Waybig (UA Finale)

* FredTatasciore: His voice in the original series.

* HeyItsThatVoice: Michael Dorn, also known as [[Series/StarTrekTheNextGeneration Worf]].

* TaraStrong: Albeit heavily warped.

* RobPaulsen

** CarlosAlazraqui: In ''[[TheMovie Race Against Time]]''.
** KariWahlgren: In the alternate reality episode, "Gwen 10".
** RichardStevenHorvitz: In the original series.

* YuriLowenthal

* StevenBlum

* TheOtherDarrin: James Remar, JohnDiMaggio in the ''Vilgax Attacks'' video game. [[hottip:*: Somewhat of a shame that Remar was used in the show and not [=DiMaggio=], as the former sounds nothing like Vilgax from the original show, while the latter does an impressive StevenBlum imitation.]]

!Dr. Animo

* KariWahlgren

* HeyItsThatVoice: Has the same as Ghostfreak (Blum in the original series and Bennett in Alien Force).
* HijackedByGanon:Dr Vicktor, the Yenaldooshi and the Mummy were all three revealed to be working for him.

* [[spoiler:KilledOffForReal: After being absorbed by Vilgax.]]

* WilWheaton

* YuriLowenthal

* JohnDiMaggio

* JohnDiMaggio

* HeyItsThatVoice: He is voiced by David Kaye, who voiced Megatron in ''BeastWars''.

* JeffBennett: Save for his debut in "Secret of the Omnitrix".

* ScottMenville

* HiddenDepth

* EverythingIsBetterWithDinosaurs: looks like an armored velociraptor with wheels as his feets.

* InformedFlaw: according to the bandai profile, his species has problem running on water due to the static electrity they produce while moving. Yet, (=XLR8=) has been seen walking on water with no such problems. Fans usually assume the suit might be protecting him.
* OurElvesAreDifferent: the bandai profile describes his species has possessing PointyEars and long hair, much like Elves. However, since (=XLR8=) wears a helmet and can't remove it (and so does Helen), this has never been confirmed. On a note, the shape of his helmet is reminiscent of the Eldars, aliens from Warhammer40000 who are basically Elves in space.

!Zs'Skayr

* AllThereInTheManual: His name was revealed through a trivia pop-up.

** [[LightningBruiser Hard Hitting Speedster]]: Ultimate Cannonbolt

* TheReasonYouSuckSpeech: Courtesy of Ben in "The Gauntlet." After they spill a smoothie on him as a prank, he chides them for pulling the same nonsense since grade school and admits disbelief that he used to be afraid of Cash.

* BewareTheNiceOnes: even though he acts sometimes a bit egocentric and immature, Ben is still a nice, kind-hearted a deeply altruistic guy. But push his BerserkButton, and you ''will'' regret it.

* FreudianExcuse: Everyone treated him like a freak and a monster because of his powers, so the unstable kid basically decided to do his damnedest [[ThenLetMeBeEvil to prove everyone right.]]

*** He [[spoiler: gets hit with this trope AGAIN in the Ultimate Alien Season One finale. Energy-induced insanity or not, he literally is forgiven for what the crap pulled after one simply "Sorry, man." See KarmaHoudini below.]]

* TheWorfEffect: He's usually always the one who gets his ass kicked the most in battle.

** Don't forget the time he survived falling back to the Earth from re-entry!

** His design and powers are similar to Randall from MonstersInc.

* MadeOfIron: Took lasers and missiles directly and only staggered.

* GripingAboutGremlins

* LargeHam

* WhenAllYouHaveIsAHammer: Kevin notes that all of Rath's species believes that anything can be solvable by hitting it.

* JokeCharacter[=/=]LightningBruiser: He's the former on dry land, but in water, he becomes the latter.

* BlowYouAway

* BreathWeapon: Upchuck can fire laser beams from his mouth (or as he called them in Upchuck's debut 'exploding loogies'), though it has only been used twice (first against the Forever King in the original series then later on against Chromastone (who had escaped from the Omnitrix) in alien force. Though he prefers to fire exploding green energy pellets instead.

* NighInvulnerability

* {{Expy}}: Of {{Ultraman}}. Right down to the + style energy beam.

* TheCameo: Made a brief appearance in "Victor: The Spoils", while Ben was unconscious, before making his official reappearance in "Prisoner 775 is Missing".

* TheOtherDarrin: James Remar, {{John DiMaggio}} in the ''Vilgax Attacks'' video game. [[hottip:*: Somewhat of a shame that Remar was used in the show and not [=DiMaggio=], as the former sounds nothing like Vilgax from the original show, while the latter does an impressive StevenBlum imitation.]]

* EliteMooks: The Flame Keepers' Circle are a lot more dangerous than his old MechaMooks.
* ExactWords: Vilgax assures his most loyal follower that's he going to "transform" the Earth.

* BigBad: The Forever King; Driscoll, who was Forever King in the original series, is half the BigBad of the fourth season (Vilgax being the other half through the "Secret of the Omnitrix" three-episode movie.) and Old George for season 2 of Ultimate Alien.

* NobleDemon: Enoch on occasion, particularly the "Ben 10" video game in which he tries to stop Vilgax and save the world, though using [[WellIntentionedExtremist extreme measures]] to do so.

* [[spoiler:{{Heel Face Turn}}]]
* {{Hypocrite}}: Doesn't like aliens living on his planet, even if they're just average people that do no harm. His legend was created when [[spoiler: an alien gave him the most powerful weapon ever created-that ''he'' created-without which George could never have beaten Diagon]].

* TheBlank: their face possess no visible features other than several red eyes that don't even move, making you wonder if they even are actual eyes.

* [[spoiler:{{Yandere}}: toward Ben, after Elena became one with them.]]

* EnemyMine: Helps Ben and his friends against the Highbreed invasion, teams up with Kevin to gain an artifact only to betray him afterwards, and [[spoiler: helps out again in Ultimate Alien's first season finale, only to make a failed backstabbing attempt in the end.]]

* ManipulativeBastard: To Gwen in his debut appearance, and later to Kevin, and later to [[spoiler: Charmcaster.]]

** Sort of an odd example of ViewersAreMorons, where they're expecting someone older or smarter (like Gwen is supposed to be) in the PeripheryDemographic to catch it, but to a little kid, he has a good-guy-sounding name.

* HiddenAgendaVillain: His true goal, to reshape the universe the way he wants, was kept hidden until his last appearance.
* {{John DiMaggio}}

* {{John DiMaggio}}

An hunter who will apparently serves as the main villain in season 1 of ''{{WesternAnimation/Ben 10 Omniverse}}''.

* WomenAreWiser

** TheLancer: Helen

* [[ImYourBiggestFan I'm Your Biggest Fan]]

* ElementalPowers:

* ChronicBackstabbingDisorder: this is considered normal in their politic system.

* TheCharmer: He has several girls that like him and doesn't mind that at all, but he doesn't actively pursue women though like a Casanova does.

** He's probably breathing a sigh of relief since he's not gonna have to massively overwork himself/run out of different voices in ''Omniverse'', considering Bumper Robinson, DavidKaye and YuriLownethal are going to voice some of the aliens along with other unannounced voice actors.

* DavidKaye: His voice in ''Ben10Omniverse''.

* YouDontLookLikeYou: In ''HeroesUnited'', he looks like a fairly normal-lloking [[http://images.wikia.com/ben10/images/8/80/Screenshot2011-11-25at83224PM.png yeti]]. In ''Omniverse'', he looks [[http://images.wikia.com/ben10/images/5/50/ShocksquatchAlien.jpg far more]] like a typical [[ShockAndAwe electric]] character, to the point he resembles a simian [[SpiderMan Electro]].

* GlassCannon: Seriously throw some [[WeaksauceWeakness water]] on this guy and he's through.

* AesopAmnesia

* TheObiWan
* PosthumousCharacter

* BadassNormal

* BrattyHalfPint

* BrilliantButLazy

* EnergyBeing

* HeyItsThatVoice

* [[TheSmartGuy The Smart Girl]]

* LittleMissSnarker

* {{Tomboy}}

* {{Tsundere}}: Type A.

* IdiotHero

* PesieveFlashback: Another ability of his is casting holograms of past events over the location where it happened.

* {{BFG}}: it can shoot beams, cut through diamond and coat itself with flame, amongst other things.