* ActorAllusion: Creator/YuriLowenthal voicing a character with multiple personas, with [[TransformationNameAnnouncement battle cries while using them]]? [[{{Persona 3}} I wonder ...]]
** Also, both of their first transformations (Swampfire and Orpheus) have fire attacks.
** GregCipes and AshleyJohnson voicing characters with a mutual attraction to each other? ''WesternAnimation/TeenTitans'', anyone?
* CashCowFranchise: Ben 10 is one of Cartoon Network's most popular multiseries, so natch.
* DawsonCasting: The casting for the upcoming live-action movie is fine, until the actor playing Ben is revealed to be [[http://www.imdb.com/name/nm0445987/ a 23-year old]]. Still, the ''last'' Ben wasn't 10, so…
* FandomNod: When Ben explains the current Sumo Slammers series to Kevin in the final episode, he has a few very... ''familiar-sounding'' complaints:
--> This isn't the best one to start with. It's not 'Sumo Slammers' classic. It's 'Sumo Slammers: Hero Generation'. [...] [[ContestedSequel It's a sequel to the original show, but they kinda' messed it up]]. [[TimeSkip It's like five years later]] and the bad guy Kanko [[HeelFaceTurn has teamed up with the hero]] Ishiyama. [[EasilyForgiven It's not very realistic]], is all I'm saying.
* FlipFlopOfGod: Not so much flip-flopping as one WordOfGod can override another WordOfGod. [=Dwayne McDuffie=] [[MisBlamed takes the heat for when this happens]].
* HeyItsThatVoice:
** Creator/YuriLowenthal is Ben.
** Creator/AshleyJohnson is Gwen.
** Creator/GregCipes is Kevin.
** Creator/DeeBradleyBaker is every one of Ben's aliens.
** Creator/PaulEiding is once again Grandpa Max.
** Creator/JulietLandau is Gwen's mom, Helen Wheels and Verdona in Anodite form.
** Creator/ScottMenville is J.T.
** Creator/KharyPayton is Manny and reprises the his role from the original series as Hex.
** Alexandar Polinsky ([[WesternAnimation/TeenTitans Control Freak]]) is Argit.
** Creator/KevinConroy is Bellicus, one third of Alien X.
** David [=McCallum=] ([[Series/{{NCIS}} Ducky]]) is Paradox.
** Creator/WilWheaton is Darkstar.
** And in the Japanese dub, Ben is [[GundamSEED Kira Yamato]] and Kevin is Sasuke Uchiha from Manga/{{Naruto}}, the latter being particularly ironic because ''Ben'' is Sasuke in the US.
** JohnDiMaggio is Rath.
** How can anyone forget Princess Attea being voiced by the [[Creator/TaraStrong original actress]] for Ben from the [[WesternAnimation/{{Ben10}} original series]]?
** Creator/KariWahlgren is once again Charmcaster.
** Creator/GeorgeNewbern is Gwen's dad, Frank.
* PlayingAgainstType: JeffBennett as Azmuth and Ghostfreak.
* TheOtherDarrin:
** Ben, Gwen, and Kevin, [[JustifiedTrope Justified by the]] TimeSkip.
** Creator/FredTatasciore was replaced as Cannonbolt and Way Big and Creator/DaveWittenberg as Upchuck, both by Creator/DeeBradleyBaker when Ben transformed into them in the second season finale.
** Creator/SteveBlum was also replaced as Vilgax due to schedule conflicts, the role being given to James Remar, who ''himself'' didn't voice the character in ''Vilgax Attacks!'', one of the video games, where he was instead played by JohnDimaggio, whose rendition of Vilgax is much closer than James Remar's. Steve finally reprised the role in ''[[{{WesternAnimation/Ben10Omniverse}} Omniverse]]''.
** When Vilgax and Azmuth use the Omnitrix in the episode ''Primus'', their transformed states use the same voices, rather than [[Creator/DeeBradleyBaker the usual guy]].
** During their appearance in the original series, Ben's parents, Carl and Sandra, were voiced respectively voiced by series regulars DeeBradleyBaker (Stinkfly, Eye Guy, Wildmutt) and TaraStrong (Ben, Ben as Upgrade). In ''Alien Force'', they're replaced repsectively by Don McManus and Beth Littleford, who played the roles in ''[[Film/Ben10RaceAgainstTime Race Against Time]]''.
* PostscriptSeason: Across its first two seasons, the show tells a sprawling epic storyline of a battle against one of the oldest races in creation, culminating in a final episode in which virtually every single dangling plot thread, character and story concept the series has set up is convincingly brought together for a dramatic final battle that ended with the saving of the entire universe....aaaand then they made a third season. The season distinguished itself by bringing back the BigBad from the original series, but ultimately achieved little other than setting up the next incarnation of the series with its finale, consisting almost entirely as it did of one-shot adventures of no consequence, with little to no use of the new ideas and concepts set up in the season premiere. The third season was quite clearly not originally planned for the final moment of season two, in which Ben looks at the Omnitrix and claims to have a new set of ten aliens he does not recognize: quite obviously intended as an open ending that was then ignored when season three began and he had his standard ten still in place.
* RealLifeRelative: For her elderly disguise (seen only in "What Are Little Girls Made Of?"), Verdonna is voiced by Barbara Bain. In her true Anodite form and the flashback to Verdonna's first meeting with Max in "Moonstuck", her daughter Juliet Landau assumes the role. As such, Landau could be thought of as a younger representation of her mother or vice versa.
* TalkingToHimself: Every single alien in the Omnitrix is voiced by Creator/DeeBradleyBaker, except for Alien X, Ghostfreak, and Rath.
* WhatCouldHaveBeen: One of the writers said that there was a big story planned for season three that involved Kevin absorbing more energy (presumably to save Gwen) and fighting against the insanity that comes with it but ultimately becoming evil. Cartoon Network approved it at first but then they [[ExecutiveMeddling chickened out at the last minute]], so the writters had to scrap that story and start a new arc for the season from scratch. This same story was rescued for the first season of Ultimate Alien but with a different approach, [[spoiler: in particular with a happy ending]].
** Also, Man of Action's original idea for the sequel series was a teenage Ben and Gwen would become mentors to a group of kids with mysterious alien powers. When they were replaced by Murakami and [=McDuffie=], the concept was changed to the Ben, Gwen, and Kevin teaming up to fight the Highbreed instead, with the "Plumbers Helpers" being the main leftover from the old concept.
* WordOfGod: One of the main writers, Dwayne [=McDuffie=], has a thread where he answers questions and brings foreshadowing to the series. Anyone who is majorly confused with the continuity errors in this show should [[http://dwaynemcduffie.com.lamphost.net/forums/viewtopic.php?f=2&t=314&start=0 check this out]]). It addresses ''many'' oddities and seeming plot holes.
** Sixsix and Sevenseven's language is too complex for translators to handle.
----