Famed hero of the Mushroom Kingdom. He's enlisted by Sonic to help locate the Chaos Emeralds to prevent anyone evil from using their dangerous powers.
- Badass Mustache: Just as luscious and full as ever.
- Bash Brothers: Of course with Luigi, and progressively with Sonic.
- But for Me, It Was Tuesday: A rare heroic example. Mario stomped Captain Basilisx's best friend into a lava pit and used his shell to slaughter the rest, but when Basilisx informs him of what he did, Mario doesn't remember it. Although Fridge Brilliance sets in when you realize that there are no lava pits in the room that Basilisx mentions. Mario may not remember it because it may have never happened in the first place, to say nothing of the fact that the way he describes the death is literally impossible to pull off in-context. The only true fact about his story is that there was indeed a third Koopa Troopa behind Door #2 of Bowser's Castle in Dinosaur Land.
- Drop the Hammer: His usual weapon of choice.
- Dual Wielding: Hammers, with the Hammer Bros. suit.
- Expy: Word of God is that he represents Goku.
- Flight: With the Cape Feather.
- Hour of Power: The Super Star power that he picks up with Sonic in original!episode 6.
- Jack-of-All-Stats: Of the 5-Man Band he fits as a balance between strength, speed, agility, endurance, skill and adaptability. Thus makes him useful in any situation.
- Kamehame Hadoken: His charged fireballs tend to use the stance.
- Living Legend: Even Sonic, whom is from an alternate universe, has heard of him!
- Playing with Fire: Fire Flowers. On top of that, they seem to give some flat boost to his durability and fighting skills—which makes sense, since in most games they give him an extra hit point on top of the typical Super Mushroom.
- Fireballs: He can shoot fireballs in this mode, one of them was even able to disrupt Mecha Sonics aim.
- Power Glows: Usually when he's picked up a Cape Feather or Fire Flower. Notably during original!episodes 2 and 6 is when both are grabbed.
- Rapid-Fire Fisticuffs: He gives Bowser his own rendition of the Hokuto Hyakuretsu Ken in the first episode of the reboot.
- Speaking Simlish: Carried this trait over from the Mario & Luigi series. Not as much in the reboot, but he still doesn't get a text box.
- Super Mode: The openings in both the original and reboot show Mario getting one by virtue of the Star Spirits. He appears in gold and white with a super cape.
- Supporting Protagonist: While it hasn't been shown to be the case yet, it's likely he'll be this in comparison to Luigi (considering Luigi's the Gohan expy here). He may also count as this in comparison to Sonic and Shadow, considering the latter two have a much bigger beef with Metallix (what with Metallix destroying Mobius and killing their friends).
Mario's younger brother and the deuteragonist of the series. He's agreed to help in the Chaos Emerald hunt, but only reluctantly.
- Bash Brothers: Naturally with Mario.
- Badass Mustache: Well, not quite as badass as Mario, but still quite a bit.
- Big Damn Heroes: He and Yoshi get one in original!episode 8. In original!episode 9 he uses the Tanooki suit's powers to free himself from Basilisx's attack and save Mario before he is killed.
- Butt-Monkey: He's carried this trait over from the series proper.
- Iron Butt Monkey: Of course, he manages to survive just about everything that ends up happening to him.
- Cowardly Lion: Emphasis on "cowardly", but he's far from just a wuss.
- Crouching Moron, Hidden Badass: Don't let that cowardly nature fool you, when he gets serious he can be as formidable as his brother.
- Drop the Hammer: Like Mario, this is also a Weapon of Choice for him.
- Dynamic Entry: In original!episode 9, Hammers Basilisx in the face upon recovering to save Mario from him.
- Establishing Character Moment: Gets an amazing one in the very first episode of the remake. After spending the remainder of the episode being afraid of Bowser, once Mario is defeated and Bowser starts moving in for the kill... Luigi jumps in between Bowser and Mario, shielding his brother with his own body. For all that he is a Lovable Coward, he is fully willing to die in a desperate attempt to save his brother.
- Equippable Ally: In both Episode 6 and 8, Luigi is used as a weapon thanks to the Blue Koopa Shell and Tanuki Suit.
- Expy: Word of God is that he represents Son Gohan.
- Fastball Special: Often performs this with others, him being the projectile.
- Foreshadowing: In original!episode 7, after being told that in the pipe maze that they could be lost forever, the professor tells him that he was just kidding, but was being serious about the pipe maze being confusing. Then, he, Yoshi, and Shadow come across a pipe that leads into a world where its really possible to end up being lost forever.
- Grievous Harm with a Body: He often gets power-ups that incorporate his body, like the Blue Shell and the Tanuki Suit. He also uses his Luigi Missile.
- Lovable Coward: Spends most of his time afraid of everything and anything, but will always come through when he is needed the most.
- Oh, Crap!: Gets an absolutely magnificent one in original!Episode 6.
- Speaking Simlish: Just like his brother, he has this trait from the Mario & Luigi games.
- Use Your Head: Seems to use this tactic more than hed like to comical proportions.
Sonic the Hedgehog
The Blue Blur and hero of Mobius. After years of trumping Eggman and his creations, one of them did the unthinkable and laid waste to the entire planet, Sonic and Shadow the only survivors. They build a capsule to travel to the Mushroom Kingdom in order to gather the Chaos Emeralds and stop Mecha Sonic/Metallix from causing any more destruction.
- Accidental Public Confession: While arguing with Shadow the Hedgehog shortly after Yoshi nearly being killed by Mecha Sonic, Shadow briefly mentioned Mecha Sonic. Mario overheard this and asked who Mecha Sonic was, causing Sonic to say he wished he would wait for having to explain who he is, but decides Mario needs to know.
- Catapult Nightmare: On original!Episode 5.
- Expy: Word of God is that he represents Future Trunks.
- High-Speed Missile Dodge: He did one in original!Episode 7, though it's subverted immediately after: the missile hits the wall and explodes, and the explosion proves realistic enough that Sonic can't outrun it.
- Hour of Power: "Well... That little experience was pretty short lived....."
- Hurricane Kick: One of his many moves.
- Laughing Mad: For a short while in original!Episode 7. Doubles as a Shout-Out to Sonic the Hedgehog 3, as the sprites used were seemingly based on the laughing sprites of Knuckles the Echidna as he appeared in the aforementioned game.
- Nice Guy: Even after all he's been through, Sonic remains polite and amiable towards Mario and company. Of course, he's still fully capable of kicking ass and taking names.
- Speed Blitz: The Light Speed Attack makes a return in episode 7.
- Super Drowning Skills: Just like in the games, Sonic sinks like a rock. Fortunately for him, Mario doesn't.
- Super Mode: The usual Super Sonic fare.
- Playing with Fire: He is also able to utilize a Fire Flower.
- Take That!: When he was 8-Bit Sonic (read: almost Classic Sonic), he made this remark.Sonic (8-Bit): What the heck? Why am I so blocky? And I've put on some weight, too! Man, this really sucks!
Shadow the Hedgehog
The Ultimate Life Form. Just as Mecha Sonic/Metallix got the seven Chaos Emeralds, Shadow had used Chaos Control to teleport them into another dimension, the Mushroom Kingdom. When Mecha Sonic/Metallix chased after them, Shadow and Sonic both followed suit so that Shadow could have revenge on the robot.
- Accidental Public Confession: See Sonic's.
- Anti-Hero: Much more violent than the rest of his comrades.
- Berserk Button: Never mention Maria in front of him. Ally or not he won't hesitate to kill you.
- The Big Guy: He seems to be written as the most powerful fighter of the Five-Man Band, and it shows—he's the only one able to even remotely keep up with Mecha Sonic's four-emerald Super Mode, with Mario (with his raw-power-boosting Fire Flower) managing one good hit and everyone else unable to get close.
- Bullet Time: Can pull this off with Chaos Control.
- Chekhov's Gun: Shadow mentions in original!Episode 5 that he can sense Chaos Emerald energy from long distances when explaining his suspicions about the "emerald" lying in front of him. This might act as an explanation as to how he'll find at least one chaos emerald while Mario and the others try to rescue Peach without him. Confirmed in the original!Episode 9 trailer, as Shadow explicitly stated that he was going to focus himself to sense the location of the sixth emerald in the desert before being ambushed by Mecha Sonic.
- Expy: Of Vegeta. Word of God didn't even need to confirm this.
- Flash Step: His Chaos Control is used for this.
- Hair-Trigger Temper: He gets rather angry easily... even more so that in the actual Sonic series.
- Heroic BSoD: It is heavily implied that Shadow's current characterization stems from the trauma of having to bear witness to Rouge and Omega, his only real friends, being outright slaughtered, as can be inferred from the flashback in original!Episode 8.
- Jerkass: His personality is pretty much a shout out alone to Dragon Ball because of Vegeta.
- Freudian Excuse: However, it wasn't his natural personality as much as him adopting it due to the trauma of his friends, Rouge and Omega, being slaughtered by Mecha Sonic.
- Jerk with a Heart of Gold: He's not evil by any stretch. He's putting in the effort to keep innocent people (and yoshis) alive and mostly unharmed.
- Kame Hame Hadoken: Chaos Spear.
- Lightning Bruiser: Able to keep up with Mecha Sonic and put up a decent fight with him.
- Memento MacGuffin: Keeps Rouge's locket with him, as shown in original!episode 9.
- Written-In Absence: Shadow is going to be absent for most of the Omega Doomship arc because he wanted to find the Chaos Emeralds himself, realizing he can't convince them to continue finding the Chaos Emeralds and leave Peach behind at Bowser's hands.
- Chekhov's Gun: Gives Luigi a 1-Up Mushroom before the heroes head off to Yoshi's Island. This ends up restoring Mario and saving the heroes from Mecha Sonic.
- Damsel in Distress: Both times by Bowser. In episode 1 she is held hostage by Kamek in a Sadistic Choice (though it was likely that Kamek was bluffing since it was doubtful that Bowser would want Peach as a Goomba), and later is kidnapped by Bowser in exchange for the Chaos Emeralds the heroes currently have in the original series.
- Princesses Prefer Pink: Still sporting her pink finery.
- Say My Name: She calls out to both Mario and Luigi in the reboot of Episode 1.
- Art Evolution: He uses Yoshi's Island sprites until original!episode 5. From original!episode 6 on he has Yoshi's Island DS sprites, while all other Yoshis keep the same.
- Badass Adorable: He's the same adorable, loyal green dinosaur from the games, and can hold his own alongside the Mario Bros., the speedster Sonic, and Shadow.
- Big Damn Heroes: He pulls one of these in original!Episode 8 alongside Luigi, and earlier in original!episode 5, knocking away Thunderfoot before he can strike Mario.
- Catch and Return: True to form, he can spit projectiles and whatever he can stuff into his mouth back to the sender.
- Expy: Of Piccolo, by virtue that the Yoshis as a whole are expies of the Namekians.
- Hope Spot: When he manages to catch Mecha Sonic in an Egg. It doesn't last long.
- Made of Iron: He's introduced just so Mecha Sonic has someone to pummel, and is fighting fit by the next episode. Then you remember Yoshi can take a lot in Yoshi's Island.
- The Nose Knows: Peach suggests asking him to help find the Chaos Emeralds using his sensitive nose, and indeed he is able to easily find one.
- Overly Long Tongue: A cornerstone of Yoshi's combat style.
- The Unintelligible: He's a dinosaur. Of course he can't speak.
Professor E. Gadd
- Absent-Minded Professor: He has his moments. He thought to build a radar designed to locate the Emerald Radar should they lose it. When Sonic points out he could have just made a second Emerald Rader, E. Gadd admits that probably would have been easier.
- Expy: Of Dr. Briefs, though he doesn't actually have a daughter in this one.
- Gadgeteer Genius: An inventor extraordinaire.
- Mr. Exposition: Boy, does he have a lot to speak about...
- The Professor: Right there in the title.
Metal Sonic/Turbo Mecha Sonic/Metallix
Trying to defeat Sonic, Dr. Eggman built several robotic copies to match the hedgehog, though all of them have failed. The last in this line was Metal Sonic, built with a fierce determination to defeat Sonic that the other bots lacked. After countless failures, Metal Sonic did something drastic, and merged with all previous Sonic Robots, becoming Turbo Mecha Sonic in the original series, and Metallix in the reboot. This fusion made Metallix decide that he was through following Eggman's orders, and destroyed him along with the Death Egg, which crashed into Mobius below. This sent Metallix on a killing spree until he had all seven Chaos Emeralds which he plans to use to become a perfect being. Before he could succeed, Shadow transported the Emeralds to the Mushroom Kingdom. Metallix used Chaos Control to follow the emeralds, and will stop at nothing to retrieve them and become perfect.
- Adaptational Badass: Even when he ended up becoming the final boss in Sonic Heroes, Metal Sonic has never been this much of a threat.
- Also to the Mecha Sonic from Sonic 3 & Knuckles. In the game, while Mecha Sonic was certainly persistent in trying to take down Sonic at the Sky Sanctuary, he was still no less beatable than any of Sonic's other Evil Knockoffs; Here, being a Fusion Dance off all those Evil Knockoffs, Mecha Sonic is Nigh Invulnerable, and hands Sonic and co. their asses just about every time they encounter each other. Likewise, while the game's Mecha Sonic is invincible in his Golden Super Mode, it's still an unstable power-up, prompting Mecha Sonic to constantly return to the Master Emerald to recover it; SMBZ's Mecha Sonic gains his Semi-Super Mode from a mere 4 Chaos Emeralds, and only loses it when Super Sonic and Super Mario knock the Emeralds out of him.
- A God Am I: He basically flaunts this towards Axem Red in episode 6.Mecha Sonic: "Monster? I'm not a monster. I'M A GOD."
- Which, in context, doubles as a shout out to one of Broly's lines from the first movie he appeared in.
- A.I. Is a Crapshoot: When Metal Sonic merged with 3 other Sonic robots: Silver Sonic, the unnamed Sonic Adventure robotnote , and Archie's Mecha Sonic in the original/Mecha Sonic in the reboot. Dr. Eggman discovered him in his new form. When the doctor threatened to deactivate him, the newly formed Turbo Mecha Sonic/Metallix decided to off his now inferior master, colony droping the Death Egg onto Mobius's surface, and eventually take the entire population of Mobius out with it.
- Apocalypse How: Managed to cause a Class-5 Apocalyptic scenario on Mobius by the time he managed to chaos control to Mario's dimension.
- Arch-Enemy: To Sonic, natch. Also to Shadow due to murdering Rouge and Omega, and shown in the intros to be Mario's.
- Arm Cannon: Mecha Sonic's arm contains one of these. He usually uses it as a machine gun (with a shotgun-racking sound effect.), but he can also fire missiles out of it (two at once, even!). He doesn't use it very often though, considering that most of his opponents are fast enough/skilled enough to avoid gunfire. It is unknown if Metallix has one as well.
- Ax-Crazy: He's a totally psychotic, sadistic bastard who's willing to do whatever it takes to collect the Chaos Emeralds. The very first thing he does upon coming into creation is crash the Death Egg into Mobius, and after beating Yoshi senseless to claim the Chaos Emerald he found, he freely admits that even if Yoshi had given him the Emerald willingly, he would have killed him just because.
- Big Bad: Of the first season, and of the entire series arguably (considering his rampage is what got the Sonic characters retreating to the Mushroom Kingdom in the first place)
- Classic Villain: A murderous psychopath out to conquer the entire omniverse.
- The Comically Serious: Had exactly one moment where he was this in the original run of the show, after the Axems did the Scouter gag.Mecha Sonic: "Just who are these idiots?''
- Dangerous Forbidden Technique: See the Shout-Out entry below.
- Despotism Justifies the Means: He only cares about acquiring the Chaos Emeralds and gaining ultimate power. He's utterly destroyed all of Mobius and Yoshi's Island in pursuit of this goal.
- Determinator: As noted by Sonic in his recalling of Mobius's fate as Metal Sonic. He will not stop at anything to achieve his goal, and may God help you if you are in his way.
- Disc-One Final Boss: According to some leaked information about the older series, he would have been this in the first out of the three planned sagas.
- The Dreaded: Scary enough to cause a Mass "Oh, Crap!" among the heroes when Shadow senses he has arrived at Yoshi's Island. Mario and Luigi in particular had never personally met him at the time.
- Establishing Character Moment: His first scene shows him killing a goomba carrying the red Chaos Emerald.
- Evil Laugh: He usually gives a wry, quiet chuckle when things are going his way, but when he sees just how pathetically easy fighting Sonic and co. is with the power of just 4 Emeralds, he lets out an absolutely spine-chilling cackle.
- Evil Knockoff: Several put into one.
- Evil Overlord: His current goal, similar to his failed attempt back in Sonic Heroes.
- Expy: According to Word of God, he is supposed to be this series' equivalent of Cell.
- Faux Affably Evil: Can display this sometimes, especially if he's winning. This is especially prominent in episode 6, though he immediately drops it once he's lost the Chaos Emeralds.
- Final Boss: If the opening sequences are of any indication, one against him will be the Final Battle of the series.
- Fusion Dance: Turbo Mecha Sonic/Metallix is the result of Metal Sonic merging with Silver Sonic, the unnamed Sonic Adventure robotnote , and Archie Comics' Mecha Sonic (for Turbo Mecha Sonic)/Mecha Sonic (for Metallix).
- Hero Killer: Not only directly responsible for effectively ending life on Mobius, he has personally executed the majority of the Sonic cast, presumably leaving Sonic and Shadow as the only ones left. He seems to be out to kill them too, in addition to acquiring the Chaos Emeralds. Let's not forget how he almost kills Yoshi in episode 3 and continuously attempts to off the other heroes as well.
- Implacable Man: He's hunted those Chaos Emeralds the entire time and has taken quite a beating, but he can still kick your ass no worse than before. In fact, he escalates it every time he's fought.
- Invincible Villain: Let's count the ways, shall we? Nigh Invulnerable? Check. Hands out curb-stomps like they're going out of style? Check. The heroes have never come close to anything resembling beating him, even on their best days? Check, check, and check.
- Just Toying with Them: He gleefully admits that the fight he has with the gang in his Semi-Super Mode - which he was winning near-effortlessly, by the way - was still just him toying with the heroes.
- Killer Robot: With emphasis on "killer".
- Knight of Cerebus: While the Mario villains have their share of comedic quirks and amicable traits, Mecha Sonic/Metallix is played completely seriously with no humorous traitsnote to detract from his viciousness. Dosen't help that even the other villains (Bowser, The Axem Rangers, etc.) are disgusted by his actions.
- Lightning Bruiser: Lets See here. Hes confirmed faster than sonic, tougher than Mario, and more powerful Shadow. Even with a team its minimal in chances of success against him, alone its suicide.
- Nigh Invulnerable: Survived the Death Egg's collision into Mobius and it's subsequent explosion. And this is him with no Chaos Emeralds whatsoever.
- No-Holds-Barred Beatdown: He's basically the king of this, to both the Axem Rangers and the heroes.
- No-Sell: He doesn't sell many things. In original!Episode 6 alone, everything the heroes and villains have is thrown at him, including an ability that had previously one-shotted all the heroes, and the only things shown to affect him at all are a surprise fireball from Mario, and a Super Mode Combination Attack.
- Oh, Crap!: When Super Sonic is priming to blast him to smithereens, he's left as frozen as a deer in headlights. Unfortunately for Sonic, his power-up doesn't last long enough for him to finish the villain off.
- Omnicidal Maniac: Fusing with three other robots turned Metal Sonic into this.
- Person of Mass Destruction: He tends to obliterate things. Has an island, a Death Star expy, and an entire planet's population on his resumé.
- Red Eyes, Take Warning: As the infamous Metal Sonic as well as Metallix in the reboot. As Turbo Mecha Sonic, it seems only whatever passes as his "whites" are red, while his "irises" are sort of orange.
- Ridiculously Human Robots: Got a similar deal here as he got back in Sonic Heroes. In fact, his design in the reboot would allow him to very nearly blend right in with the characters of the Mega Man universe.
- Power Copying: Like in Sonic Heroes, Metallix can copy other abilities and use them himself. In the original run, he demonstrated Chaos Control, Chaos Blast, and the Light Speed Attack.
- He once used Akuma's "Shun Goku Satsu" in Semi-Super Mode. Against an Axem Ranger. That poor villain...
- What's worse: That wasn't even his entire attack: Shortly afterwards, he then punched Red to the Ground, punched/grabbed Red's back from below, and then kicked him into the air before vaporizing him with a beam in a manner similar to how Goku broke Nappa's back and how Vegeta killed Nappa respectively.
- The Sphere of Destruction that he used on Yoshi's Island is very reminiscent of Frieza and his planet-killing Death Balls.
- His 7-emerald transformation in the original, Metallix, appeared to be a stylized version of Sonic 3 Mecha Sonic's head and Bass' body. In the reboot, Metallix was redesigned and became the character's new base form, replacing Turbo Mecha Sonic outright. The redesign's aesthetic resembles to varying degrees the base Metal Sonic, Neo Metal Sonic, and Bass.
- He once used Akuma's "Shun Goku Satsu" in Semi-Super Mode. Against an Axem Ranger. That poor villain...
- Some Kind of Force Field: Activated what appeared to be a Lightning Shield to block the Chaos Emerald-powered Breaker Beam the Axems used on him. He wasn't even the target at the time.
- Super Mode: While his standard form can technically qualify, due to it actually being a Fusion Dance-style transformation from Metal Sonic into this form, known officially as "Turbo Mecha Sonic", he has a Semi-Super Mode with 4 Chaos Emeralds, which resembles the original Mecha Sonic's Super Mode, and if Alvin had not cancelled the series, he would have gotten an even stronger form with all 7 Chaos Emeralds that would have gone by either "Metallix" or "Master Mecha Sonic". In the reboot, "Metallix" is his new Fusion Dance-induced base form, replacing Turbo Mecha Sonic from the original, with a 7-emerald transformation being unknown at this time.
- Teleport Spam: While fighting the Axem Rangers in Semi-Super Mode, he teleported at a rapid pace as he was attacking one of them.
- There's No Kill Like Overkill: His preferred method of execution. More Dakka is on the less extreme end of the spectrum.
- Unreliable Narrator: In Sonic's nightmare he stated that he was effectively doing his job as per Dr. Eggman's programming. Taking Sonic Heroes into consideration...
- With Great Power Comes Great Insanity: Him witnessing the carnage he wreaked upon the world set off his current Omnicidal Maniac personality.
- Would Hurt a Child: Ignoring for a moment that the majority of the heroic Sonic cast are teenagers, there were still a few who were younger than teen age, like Tails, Cream, and Amy Rose. No bonus points for guessing who killed them.
King of the Koopas. Bowser has tried for years to conquer the Mushroom Kingdom and take Princess Peach as his bride. He has failed, time and again thanks to the Mario Bros. Recently he has learned about the Chaos Emeralds, and has rallied his army to find them and use their power to finally succeed in taking over the world and defeating his rival for good.
- Arch-Enemy: Mario's, naturally.
- Art Evolution: His appearance in the earliest arc has him using his Superstar Saga spritework, resulting in somewhat Limited Animation. His reappearance later on uses his more flexible sprites from Super Princess Peach, and in the reboot he uses sprites from Bowser's Inside Story.
- Bad Boss: Bowser is portrayed as a worse boss than he is the actual video games.
- Breaking the Fourth Wall: Done very literally with his first defeat in both versions of the show: After two unknown entities (Sonic and Shadow) knock away Kamek while he was holding Peach hostage, Mario capitalizes on the distraction and throws him off the racetrack/battlefield by the tail. Bowser is then seen being hurled away and (in a scene taken directly from the ending of Mario & Luigi: Superstar Saga) crashes into the "screen" hard enough to crack it before slipping down as if hitting glass.
- Breath Weapon: (Combined with Kamehame Hadouken).
- Chrome Champion: Metal Bowser, in the first real battle of the series. Mario has a difficult time defeating him. It takes the timely arrival of Sonic and Shadow's capsule for Mario to even stand much of a chance in the fight.
- Even Evil Has Standards: He did not take Yoshi's Island's destruction very well, especially when it was not under his orders.
- Expy: After he decides that he wants to get his hands on the Chaos Emeralds, he becomes one of Commander Red.
- Gosh Dang It to Heck!: "WHAT THE DEUCE???!!!"
- Harmless Villain: Gets the tar beaten out of him by Mario. Again. (Subverted somewhat, because this particular scheme had him VERY close to winning and it took what is arguably a Deus ex Machina to stop him.)
- Not-So-Harmless Villain: In the later episodes.
- Hair-Trigger Temper: When Kammy intrudes on him during his tantrum, she's promptly blasted.
- Kamehame Hadouken: He does it with fire breath!
- Made of Indestructium: Metal Bowser, to the point where he takes Mario's Kamehame Hadoken fireball like it was nothing. To put this in perspective, even four-emerald Mecha Sonic visibly flinched from a fireball of equal power. Bowser didn't even blink.
- Mighty Glacier: He's the same mix between this and Lightning Bruiser as The Incredible Hulk is; up close, he's relatively slow and clumsy, otherwise, he's extremely fast for his size.
- No-Sell: To everything, as Metal Bowser. Sonic and Shadow's heavy futuristic-metal capsule falling from some distance and landing on him is the only thing that proves effective.
- Villainous Breakdown: He suffers something like this after his defeat at Mario's hands and has a LONG tantrum extending into original!episode 7.
Dr. Ivo "Eggman" Robotnik
Mad Scientist and former enemy of Sonic. In his attempts to conquer Mobius, Dr. Eggman started to build robotic versions of Sonic to defeat his biggest opposition to world domination. His last attempt at this approach, Metal Sonic, eventually turned rogue and became Mecha Sonic/Metallix. After confronting his disobedience, Mecha Sonic/Metallix destroyed the Death Egg and Eggman with it. He actually survived and travelled to the Mushroom Kingdom as well, throwing his lot in with Bowser to presumably enact his revenge.
- The Dragon: To Bowser.
- Expy: Of Dr. Gero, where in his creation proves more dangerous than himself and betrays him.
- Face Framed in Shadow: Not that it helps any, due to his distinctive silhouette.
- Killed Off for Real: Assumed when the Death Egg crashed into Mobius. [[spoiler:It didn't take. Or did it? A theory goes that this is not exactly Eggman...
- Not Quite Dead: Possibly. He's teamed up with Bowser, though we have no way of knowing if this is the real Eggman or a certain imposter.
- Mad Scientist: It wouldn't be Eggman if he wasn't this, now would it?
- The Man Behind the Man: He (if it is him indeed) seems to be manipulating Bowser.
- Unwitting Instigator of Doom: He was the one who created Mecha Sonic after all.
- Villain Team-Up: With Bowser although hes surprisingly a little submissive and patient in this one.
BasilisxA captain in Bowser's army. Basilisx was experimented on to give him greater powers to win against Mario, whom he has a personal grudge against.
- Avenging the Villain: His brother apparently, but its ambigous if its right.
- Combat Pragmatist: Zigzagged. He could have just used the Stone Gaze to turn Mario to stone immediately, but he challenged Mario to a one-on-one fight instead, preferring to kill a flesh-and-blood Mario. In the actual fight, however, he has absolutely no qualms about using Poison Mushrooms to weaken his opponent or Luigi as a shield/bludgeon.
- Duel Boss: He forces Mario into a one on one.
- Elite Mook: He's basically a Koopatrol on steroids.
- Even Evil Has Loved Ones: He bears a personal grudge against Mario and wants him dead for killing his best friend during the events of Super Mario World.
- Kiai: Utilized this during his fight with Mario at one point.
- Original Character: Doesnt exist in the games.
- Red Eyes, Take Warning: One of the major differences between him and a regular Koopatrol.
- Shout-Out: His finishing move against Mario was Vega's Bloody High Claw.
- Sssssnake Talk: Even his name gets in on it. Just try saying that last bit.
- Story-Breaker Power: Can turn anybody into stone with a single glance, leaving them motionless and powerless to do anything against him. He could have killed all the heroes (minus Shadow) without any actual effort had he not wanted to choose to kill Mario fresh instead of destroying his stone statue.
- Super Soldier: Again, he's basically a Koopatrol on steroids. You can't get any more blunt than that.
- Taken for Granite: His specialty is turning enemies to stone.
- Wolverine Claws: Bears these, and is very adept with them.
The Koopa Bros.
the Star Spirits incident. The Koopa Bros. caught wind about the Chaos Emeralds and manage to steal one from the heroes. Once they realize how powerful they can become with the Emerald's power, the Koopa Bros. decide to leave Bowser's army and gather them for themselves.
- Adaptational Badass: A large part of it is due to the Chaos Emerald's power, but even without it, were way more of a threat then they were in the games.
- Combination Attack: Just like in Paper Mario, they can stack up and spin. This attack is amplified with the Chaos Emerald in hand.
- Continuity Nod: Their defeat by Mario was referenced in Paper Mario, and this time, they actually have a chance to exact revenge on their earlier defeat at Mario's hands (although they attempted to have revenge on Mario late in their original game, they weren't able to get the chance because Jr. Troopa brushed them away before they could fight Mario.)
- Curb-Stomp Battle: They were on the receiving end of this in original!Episode 6. What the three-way battle between them, the heroes, and the Axems would most likely have achieved eventually was achieved in one blow by Mecha Sonic.
- Expy: Of the Teenage Mutant Ninja Turtles.
- Flanderization: Yellow was even more prone to doing stupid stuff than before. In the game he was originally in, while he wasn't necessarily the smartest of the brothers, he certainly had his moments of at least cleverness, as he was the only one of his brothers who actually succeeded in (albeit temporarily) capturing Mario (by creating a makeshift "?" block to use to activate a trap door below him that leads to a jail cell.
- Kill 'Em All: Still unconscious on the island, they were vaporized along with Yoshi's Island when Mecha Sonic charged that freaking miniature sun. They are not coming back.
- Saying Too Much: Red silences Yellow for confessing that they acquired the Emerald Radar in the Axem Rangers' presence.
- The Starscream: After beating Mario, Sonic, Shadow, and Luigi due to their unintentionally activating the Chaos Emerald's powers, they considered backstabbing their boss (who is heavily implied to be Bowser) and calling the shots.
- Too Dumb to Live: They have their moments. Like when one of them tells the Axems about the emerald radar, or when it turns out they've been holding it upside down.
- These are all just from Yellow. The other 3 are much smarter. Of course, one should question why they let the dumb one hold the radar in the first place...
- Totally Radical: Like in the games, they speak like they're stuck in the 90's.
The Axem Rangers
The Axem Rangers, once destroyed by Mario, have been rebuilt by their master Smithy with new bodies and power. After discovering a Chaos Emerald on Yoshi Island, the Axem Rangers enslave the population and have them mining the island to find more "amethysts of might" so that they can restore Smithy to his full power.
- An Axe to Grind: All of the Axems carry pole-axes.
- Back from the Dead: Axem Red says Smithy rebuilt the team to have them find new sources of power.
- Braggart Boss: Axem Red boasts about the power of his secret weapon to a 4-emeralds buffed Metal Sonic. It doesn't end well.
- Came Back Strong: Were upgraded as well when revived by Smithy.
- Combination Attack: Axem Green and Black's special skill, combining into a large spinning wheel, which can cleave through stone.
- Drop the Hammer: Axem Yellow can form his hands together to make a hammer. It can split mountains, too!
- Dumb Muscle: Yellow is accused by Green of being an imbecile, and has enough strength to split a mountain nearly in half.
- Even Evil Has Standards: Axem Red was quite angered at Mecha Sonic due to his murdering his fellow members in such brutal methods.
- Everything's Better with Spinning: Axem Green and Black's special again. Also, all rangers appear to be able to pull off a tornado spin attack.
- Expy: Considering their role early on, as well as the fact that they debut in the series equivalent of Namek, one could argue that the Axem Rangers X are the SMBZ equivalents of the Ginyu Force.
- Face Fault: Axem Yellow causes one among his team after saying they should get McGoomba's after being discovered by Mario.
- Five-Man Band
- Good Old Fisticuffs: Axems Yellow and Red can fight like this too when deprived of their axes.
- Half the Man He Used to Be: The fates of Pink and Black, and a vertical variation for Yellow.
- Heart Symbol: Axem Pink has one appear in the air at the end of her special combo.
- Kill 'Em All: Like the Koopa Bros., they ain't coming back, and given their brutal deaths, yeah...
- Alvin Earthworm confirmed that they would have played a large role in season two.
- Meaningful Name: AX 'EM. Duh.
- Off with His Head!: The fate of Green. If that wasn't enough, Mecha Sonic even ups it by actually crushing Green's decapitated head with his bare hands.
- Shout-Out: "Hey Red, what does the scouter say about his power level?"
- Also, the Axem Rangers' "upgraded bodies" are that of Zero's regular form (Zero Series), Zero's Defense Form (Zero Series), A customized version of the Zero model depicting Black Zero, GutsMan.EXE, and Roll.EXE for Axems Red, Green, Black, Yellow, and Pink. Their pole-axes (except for Yellow's) are the Triple Rod sprites from the first Mega Man Zero game with the spearhead replaced with color-matched axeheads.
- The Smurfette Principle: Axem Pink is the only female member of the team.
- Wave Motion Gun: Axem Red's secret weapon (which he seems to pull out of hammerspace), not to mention the Blade's Breaker Beam.
- The Worf Barrage: Axem Red's secret weapon, again and the Breaker Beam, again. Both times toward Mecha Sonic.
- "X" Makes Anything Cool: The new addition to their team name.
- You Monster!: Red says this to Mecha Sonic after he killed every other Axem Ranger, to which Mecha responds:Mecha Sonic: Monster? I'm not a monster. I'M A GOD.
Wario and Waluigi
Wario and WaluigiThe Almighty Alteregos. After the tournament is interrupted, the duo spy on the heroes and learn about the Chaos Emeralds. Wario and Waluigi decide to follow and steal the Emeralds from the heroes to strike it rich.
- Badass Mustache: Both of them.
- Butt-Monkey: Waluigi seems to suffer more than Luigi. Much of his abuse is brought on by Wario.
- Combat Pragmatist: Wario, the first episode of the reboot sees him have Waluigi distract Mario before hitting him the back so Waluigi can get some decent hits in.
- Combination Attack: In the reboot, Wario has Waluigi light one of his farts on fire. Making for a powerful blast. This is a Shout-Out to one of Alvin's contributions to the Beat Up Sandbag collab, where Wario and Waluigi did the same thing.
- Fat and Skinny: They're the Mario Brothers, with their physical traits exaggerated. Wario being bigger and fatter, Waluigi being taller and lankier.
- Gasshole: Wario.
- Goldfish Poop Gang: Most of the other antagonists are actual threats. These guys... well, they'd be lucky to even get in the heroes' way successfully.
- Greed: Their goal in the series is to steal the Chaos Emeralds and sell them for a high price.
- Involuntary Shapeshifting: Wario will use Waluigi for whatever he needs. Including an swimming ring in the original run and a baseball bat in the reboot.
- Jaw Drop: Both are left speechless when Mario is revealed to have survived their Combination Attack.
- Man Bites Man: Wario tries repeatedly in the reboot to bite Mario in half.
- Mythology Gag: Wario "summons" Waluigi (who was already sort of standing in Wario's corner outside the battlefield until that instant) with an Assist Trophy, just like what might happen in Super Smash Bros.. The whole situation is promptly lampshaded by their reactions to the item's immediate effect.
- Pre-Asskicking One-Liner: "Have a rotten day!"
- This Is Gonna Suck: Wario lets out a worrisome "Oh no..." just as the giant Bob-omb lights its fuse.
- Those Two Bad Guys: In the grand scheme of things, they're not a real threat.