Mikey encounters a giant crocodile in the sewers. When the Turtles track it down, they discover a big surprise...First appearance of Leatherhead
This episode provides examples of
- Arbitrary Skepticism: Michelangelo is the first to encounter Leatherhead, and when he tells them, the rest of the Turtles disbelieve him. At this point in the series, they have already encountered/know the existence of ninjas, criminal organizations, superheroes, cryptids, aliens, and mystical forces, yet a giant crocodile (mutated in the same way they were) is unbelievable.
- Bittersweet Ending: Ends with the turtlesí old lair caving in on Leatherhead and Mikey pities him for being alone.
- Continuity Nod: When Mikey tells his brothers he's seen a giant croc in the sewers, Leo reminds Raph that they encountered a giant albino crocodile when they were children, a reference to the Season 1 episode "Tales of Leo"
- Evil Knockoff: Baxter Stockman's Turtle-bot.
- Metamorphosis: Leatherhead's back story and mutation are revealed
- Shout-Out: Mikey imitates Steve Irwin when he goes searching for Leatherhead
- Reluctant Monster: The Turtles initially mistake Leatherhead for a mindless monster, until they learn the truth