Name: Leonardo

Designer: Kevin Eastman, Peter Laird

First Appearance: Teenage Mutant Ninja Turtles #1

Weapon: Katana Blades

Profile: The elder of the turtle brethren and self appointed leader. His calm nature and appreciation for art, philosophy and training makes him the turtle that mirrors Master Splinter the most. Due to his superior discipline and level headed approach, he often butts heads with his brothers, in most cases Raphael.

His appearance and personality remains very similar through all the different Turtle universes.

Name: Michelangelo

Designer: Kevin Eastman, Peter Laird

First Appearance: Teenage Mutant Ninja Turtles #1

Weapon: Nunchaku

Profile: In the original comics, Mike, while fun loving, is also highly competent and acts as communicator between his more rivaling brothers in shells. He also expands into arts and literature while showcasing a more emotionally balanced character, essentially making him the most human out of the 4. In the 1987 cartoon, his role was relegated into comic relief with a surfer dude personality. Most of the pop culture elements of TMNT comes from Mike.

UK censorship changed his nunchuks into a grappling hook.

Name: Donatello

Designer: Kevin Eastman, Peter Laird

First Appearance: Teenage Mutant Ninja Turtles #1

Weapon: Bo Staff

Profile: A tech wiz and general genius, Donatello is responsible for most of the technology and machinery that the Turtles use throughout each universe. While he is far and beyond the most intelligent of the four shell shockers, he lacks the leadership qualities that Leonardo possess, but he is often established as second in command.

Like the others, Donatello is more goofy and wisecracking in the cartoon compared to his comic counterpart, though his establishing qualities remain more or less the same.

Name: Raphael

Designer: Kevin Eastman, Peter Laird

First Appearance: Teenage Mutant Ninja Turtles #1

Weapon: Sai

Profile: The black sheep of the group. Raphael suffers from issues of anger and extreme frustration rooted in the fact that they live their lives secluded and hidden, always seen as outcast. His anger most often leads to fights with Leonardo over leadership and family issues, though he is also shown to have strong love and compassion for his brothers and their master.

The comic and movie versions of Raph keeps his anger in center of his character, but the 1987 cartoon drastically alters his personality to a wisecracking new yorker with some rebellious elements. The 2003 cartoon is closer to his comic book persona.

Name: Master Splinter

Designer: Kevin Eastman, Peter Laird

First Appearance: Teenage Mutant Ninja Turtles #1

Weapon: Staff (Master of all weapons)

Profile: In the comic, movies and 2003 toon, Splinter is Hamato Yoshi's pet rat, mimicking Yoshi's movements to become a master of Ninjitsu. Yoshi, a highly regarded member of the foot, is forced to flee to New York due to the accidental murder of Oroku Nagi, brother of Oroku Saki. When Yoshi is murdered at the hands of Saki, Splinter settles in the sewer along with his four turtles that has fallen down to the sewer along with a mysterious ooze. Due to this ooze, they mutate into their anthropomorphic forms.

In the 1987 cartoon, Splinter is Hamato Yoshi due to him touching the chemical ooze and interacting with rats in the sewers after fleeing to New York.

In all universes, Splinter is a noble martial arts master with incredible knowledge and combat skills, as well as a deep love for the four turtles who he considers his sons.

Name: April O' Neil

Designer: Kevin Eastman, Peter Laird

First Appearance: Teenage Mutant Ninja Turtles #2

Weapon: Katana (in some depictions)

Profile: The Turtles's closest friend, April O'Neil sports very different personal traits depending on the universe.

In the original comic, Neil is the assistant to scientist Baxter Stockman in the creation of Mousers, but eventually breaks away and is saved by the TMNT. Her character is a dark haired, emotionally complex individual with more a depressive undertone. The 2003 cartoon based April on this character though without the darker elements.

The 1987 cartoon portrays April as a hot-on-the-case tv journalist who is always eager to get the story. She is saved by the TMNT from Bebop and Rocksteady and befriends them. Like all characters in the 1987 cartoon, her personality is a rather one dimensional wise cracker and she is often kidnapped for the Turtles to rescue.