In the Mirage comic books, Michelangelo was initially depicted as fun-loving, carefree, happy-go-lucky, and, while not as aggressive as Raphael, always ready to fight.

In the one-shot story, Michelangelo adopts a stray cat (which he names Klunk) and also stops thieves from stealing toys meant for orphaned children.

A scene shows him lashing out at his surroundings and repeatedly punching the wall of the barn until it breaks, then collapsing on it despondently, anger spent.

In the story arc City at War, Michelangelo instantly bonds with Casey Jones' adopted daughter Shadow, who nicknames him "Rooish".

These stories also laid the foundations which demonstrated his closeness with his brother Donatello, their laid-back natures separating them from the more contentious Leonardo and Raphael.

The ordeal results in Mikey's personality taking a very dark turn, having been hardened by the cruelty of the extrajudicial prison and Azokk's death.

He also shows signs of intelligence when he decodes ancient Japanese text in the "Ashi no Himitsu" book that tells the secrets of the Foot Clan.

Set in a dark future where New York has been conquered by the Shredder's grandson Hiroto and the Foot Clan, Michelangelo is the last of the turtles alive; Raphael drowned trying to kill Karai after her attack nearly killed Splinter (Karai was left in a permanent coma by the same attack), Leonardo and Casey Jones were blown up by Baxter Stockman's Mousers helping their allies escape, and Donatello and Splinter were betrayed and assassinated during attempted peace talks.

Michelangelo returns to New York after years of training with his brothers' weapons, but his initial assault on Hiroto's fortress fails and he nearly commits seppuku from shame, only surviving because he passed out due to blood loss before he could finish the job.

He leaves his journal with April and Casey, who are shown making plans to mutate a new quartet of turtles to continue the legacy of their fallen friends.

The sequel series The Last Ronin: The Lost Years alternates between April and Casey training the new Turtles and flashbacks looking at Michaelangelo's global travels between him learning of Splinter and Donatello's deaths and his return to New York.

To compensate for this, the American showrunners dropped the nunchaku from the series entirely in the fourth season, replacing them with a grappling hook called the "Turtle Line" that served as Mikey's signature weapon for the rest of the show's run.

[3] The live-action "Coming Out of Their Shells" concert tour, whose initial show at Radio City Music Hall would be released on Pay per view and later VHS, would see Michelangelo take the role of the band's lead singer and guitarist.

The song manages to bring the Turtles around, and the team immediately begins making plans to defeat Shredder's machine and army, which ultimately succeeds.

In the Fast Forward episode Timing is Everything when Michelangelo was talking too much, Splinter flipped over the seat he was sitting on causing him to fall on the ground, replying afterwards that "Somebody had to do it.

While there they helped Master Splinter and the Ancient One win a fight against a ghost that was sent by the Foot Mystics to revive the Demon Shredder and that is when they gain their ninja masks.

Leatherhead also appears to care greatly for Michelangelo and is distraught when he believes he has fatally injured him, but delighted to discover that his fears are unfounded when he finds out that the turtle is alive and well.

In the Season 2 finale, he became the Battle Nexus Champion, considered the best fighter in the multiverse, but his initial victory was due in part to several very lucky breaks (with Raphael even referring to it as "sheer dumb luck, emphasis on the 'dumb' part), including Splinter withdrawing to allow his sons to progress and Leonardo being eliminated by poisoning (although Mikey did defeat Raphael and Donatello was knocked out earlier).

However, he eventually gets tired of their laid-back attitudes and yells at them when they don't take the 2003 incarnation of Shredder seriously, proving even this version of Mikey has his limits to fooling around.

Whilst he is more interested in comics and cartoon shows (such as Crognard the Barbarian, which is a parody of Thundarr the Barbarian; and Super Robo Mecha Force Five, which is a parody of both Voltron and Super Robot Monkey Team Hyperforce Go!, the latter of which also created by the series creator Ciro Nieli) than animals, he adopted a cat April found on the street after the cat ate some mutagen Mikey had spilled ice cream in, resulting in the arable and delicious Ice Cream Kitty; most likely this incarnation's version of Klunk.

Michelangelo's relationship with Ice Cream Kitty parallels Raphael's with pre-mutation Spike, wherein he will tell Ice Cream Kitty his innermost feelings and fears, and not feel judged by them - as often his brothers find Mikey's concerns and thoughts too silly to be worth their time, though said concerns end up being true quite often; such as the existence of the Kraang in "Rise of the Turtles Pt1".

In the 2018 animated series, Rise of the Teenage Mutant Ninja Turtles, Brandon Mychal Smith voices a Michelangelo described as "the youngest brother, an artist and awesome skateboarder with a wild colorful, and imaginative personality.

He speaks with a distinctive California accent (that was imitated in the later versions of TMNT), In the first movie, he and Donatello (who was instead portrayed as the skateboarder of the team) were regularly paired together while Leonardo and Raphael were arguing.

In TMNT, Mikey has taken to performing at children's birthday parties as "Cowabunga Carl" in order to help make ends meet to support his family.

It becomes apparent early in the film that the physical and emotional absence of his older brothers has finally begun to affect the outgoing Michelangelo; when he returns home from work and announces his presence and no one acknowledges him, he sighs "Whatever..this place used to be fun".

Upon Leonardo's return from Central America, Mikey gives his oldest brother an enthusiastic hug, falling over the couch and tripping over furniture in his excitement.

Mikey's lively and innocent demeanor returns in full force when he is in the protective presence of his three brothers again, his good-natured jokes and brief commentaries lightening even in hard situations.

Clearly, despite the hardship that his family has recently experienced, Michelangelo has retained much of his usual goofy, laid-back personality and still remains the main form of funny.

In the video games based on the 1987 animated series, Michelangelo is virtually identical to Leonardo on every level except attack range.

Michelangelo is featured as one of the playable characters from Teenage Mutant Ninja Turtles as DLC in Injustice 2, voiced by Ryan Cooper.