Leonardo

One of four baby turtles accidentally exposed to a mutagenic ooze in the New York City sewers, Leonardo was raised and trained in ninjutsu by the rat sensei Splinter, emerging as the disciplined, katana-wielding leader of the Teenage Mutant Ninja Turtles.

Few characters from the Bronze Age have proven as enduringly iconic as Leonardo, who burst onto the scene in the landmark 1984 debut of Teenage Mutant Ninja Turtles #1 — a scrappy, self-published Mirage Comics sensation co-created by Kevin Eastman and Peter Laird that rewrote the rules of indie comics. Over an extraordinary four-decade publishing life stretching from 1984 all the way to 2026, Leonardo has anchored the TMNT universe across hundreds of appearances, sharing adventures with beloved figures like Splinter, April O'Neil, Casey Jones, and his brothers Michaelangelo and Michaelangelo. With six key-issue appearances to his name and even a surprising footprint in titles like Savage Dragon, he's a character whose reach extends well beyond any single corner of the comic book world. Whether you're a lifelong shell-head or just discovering the original Mirage run, Leonardo is essential comics history — a Bronze Age original who has never stopped mattering.