He is voiced by Wayne Grayson who is famous for voicing as Joey Wheeler from Yu-Gi-Oh!.
Michelangelo has sanguine temperament which means he is care-free, artistic, and very extroverted.
Michelangelo is slightly more immature than in the 1987 series and likes to tease and annoy his brothers, especially Raphael, to whom Michelangelo is the foil. In fact, a running gag is that whenever Michelangelo says or does something excessively outrageous, usually involving a catch-phrase from the 1987 show, one of his brothers (usually Raphael) will slap him on the head or when he does something stupid Donatello usually tends to smack him with his Bo staff. Other characters such as Master Splinter and the Ancient One have picked up on this habit, but usually, use it only whenever he actively disobeys.
With Raphael's attitude, and Leonardo's extreme discipline, Mikey seems to be closest to Donatello (however, he is still very close to his other brothers).
Mikey is regularly treated as the youngest brother and little is expected of him, although he has proven to have exceptional speed and agility. He has shown empathy for others, as proven in particular by his adoption of Klunk, a stray kitten and his friendship with Leatherhead.
In some episodes, Mikey takes on the role of a costumed superhero called "Turtle Titan." While having no superpowers and gadgets, he proves himself quite effective in his own right and even befriends other superheroes, such as the Silver Sentry and the Justice Force. As Turtle Titan, Michelangelo uses grappling hooks as both a weapon and a mode of transportation, and a small shield used for protection and as a throwing weapon.
Although not shown as particularly focused on ninjutsu, preferring to spend his time reading comics or watching movies, Michelangelo is quite an effective fighter. In the Season 2 finale "The Big Brawl," he became the Battle Nexus Champion, the best fighter in the multiverse. However, when fighting in the Tournament, he only actually won one fight properly. His first round was against Splinter, who surrendered, his second round was against Raphael, whom Mikey 'beat' by just being annoying and causing Raphael to charge into a wall by accident. Michelangelo actually won his third round, but his fourth round was won out of pure luck. As a result, he became cocky about his victory.
On the other hand, Michelangelo later won a rematch against the last finalist completely fairly, and earned a medal of honor for his behavior during the battle. In some episodes - particularly Return of the Justice Force, Touch and Go, Reality Check, Membership Drive and The Unconvincing Turtle Titan - Mikey even demonstrates quick wits and intelligence, aiding his allies and brothers with decisive ideas. While this proves he is actually more intelligent than he lets on, it is implied that he has very little interest in seriously focusing his intellectual development.
According to Splinter, Michelangelo has the most raw talent of the four, but because of his incredibly limited attention span, it's very unlikely he will ever meet his true potential. In Same As It Never Was, the dystopian version of Michelangelo has devoted his whole life to surviving without the Shredder's detection - so it is very possible that the Michelangelo seen in this episode is the Michelangelo who has reached his full potential. As far as this incarnation of the Turtles goes, Michelangelo is so far the best (possibly the only) cook in the group. In The Shredder Strikes Back (Part One), Mikey is shown cooking breakfast. Though he does mess up the fried eggs and asked "Hey, scrambled's okay with everybody, right?" (this is met with a chorus of "Again?") Raphael later comments "Say what you will about Mikey; the guy knows how to scramble an egg."
In The Darkness Within, his worst fear is shown to be betrayed by his own brothers. He encountered Leo in his nightmare where he revealed to replace his left arm for tentacles (due to choosing to side with the creature that attacked them) and turned against him.
Michelangelo is the youngest brother, also appointed to be "the one with the brightest fire" or with the most potential by The Ancient One. Master Splinter also claims a few times that Michelangelo obtains the most "raw talent" of all the brothers. Although, both Master Splinter and The Ancient One, say because of Michelangelo's lack of focus and interest in training, he will probably never meet his full potential. Michelangelo also claims many times in this series that he wishes not to be so serious and focused like his eldest brother, Leonardo. He also tells his other brothers to "chillax" and not be so serious all the time.
His agility and speed also play a bigger role than in the comics or other TV series and movies. It is shown in activities such as training runs, fights, and training that Michelangelo clearly is the fastest of the four, in which is brothers are constantly having to catch up with him. It also plays a role in the 1st season when Michelangelo and Raphael are fighting, that Michelangelo keeps taunting Raphael, but because of his speed, Raphael cannot tackle him. This is shown more than once. His speed was the main reason he won The Battle Nexus, along with his ability to "get under people's skin" and taunt them. He is also portrayed as the best gymnast of the four. This is true partly because Master Splinter always sends him off to do backflips or extra training as punishment for goofing off or losing focus. Both of these abilities allow Michelangelo to taunt his opponents and beat them quickly without getting hurt by his opponent in the process.
He has shown innocent empathy for others as shown in particular by his adoption of Klunk the stray kitten, to whom he is very close and also by his relationship with Leatherhead. It is his initial awareness of Leatherhead's humanity which ends up forging the bond between the crocodile and the other Turtles. He enjoys Leatherhead's company, although he can tease him on occasion against his better judgment. However, he cares greatly for the crocodile and is quick and willing to forgive and reassure him when a rampaging Leatherhead injures him in a blind, nightmarish rage in the episode 'Hunted.' 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.
As in the Mirage comics, Michelangelo is an avid fan of comic book superheroes. In some episodes, he takes on the role of a costumed super hero called "Turtle Titan" and befriends other superheroes such as the "Silver Sentry" and the "Justice Force". As Turtle Titan, Michelangelo uses grappling hooks as both a weapon and a mode of transportation.
Although not shown as particularly focused on ninjutsu, preferring to spend his time reading comics or watching movies, he is quite an effective fighter and in the Season 2 finale, he became the Battle Nexus Champion, considered the best fighter in the multiverse. Although his 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), Michelangelo later won a rematch against the last finalist and earned a medal of honor for his behavior during the battle, with his ninjutsu prowess being spurred when the opponent revealed that he intended to kill Raphael, Leonardo and Donatello as well after killing Michelangelo in battle, prompting the latter to recall Leonardo's words on how if one of them went down, then all of them would go down as well.
In the crossover movie Turtles Forever, Mikey is the only Turtle who initially likes their comedic 1987 counterparts (he is especially fascinated by the initials on their belt buckles). 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.
- In early profiles of the 2003 animated series, Michelangelo is regarded as being both the most athletic of the four, and as possessing the single greatest potential in the martial arts out of the quartet, although unfocused on training mentally (though those are admittedly old profiles and may have been early plans for the character, he has certainly proven he is an effective fighter when need be) which prevents him from reaching his fullest potential. This profile statement has since been repeated in the profile of Michelangelo in the lead-up to the debut of the Fast Forward season which began airing on July 29, 2006.