Leatherhead is staying with the Turtles for the time being, but Bishop's experiments have left him with uncontrollable side-effects. To make matters worse, there's a big game hunter prowling the sewers...

----
!! This episode provides examples of

* AdaptedOut: The African poacher-hunter who went after Marlin in the original Mirage story isn't included in this episode and Leatherhead instead is the one who defeats Marlin in the end.
* CloudCuckooLander: The hunter.
* CradlingYourKill: Leatherhead cradles Mikey remorsefully after he [[spoiler: thinks he's killed him]].
* DiesDifferentlyInAdaptation: At the time this episode premiered, Marlin was killed by an African poacher hunter in the comics while in this episode, Leatherhead is the one who takes down Marlin himself. Though in Mirage, Marlin would reappear again several years later, having survived his apparent death and goes after Leatherhead and the Turtles again, only to suffer a different death when a giant sea monster eats him. Either ways, his first apparent death and second seemingly final death in the comics differ from his fate in this episode.
* EgomaniacHunter: Jack Marlin (the hunter)
* EnemyWithin: Leatherhead's opening narration, and inner rage
* HairTriggerTemper: Leatherhead's anger issues this seaon reach a boiling point.
* IAmAMonster: Leatherhead says this word for word after he attacks Mikey
* ICallItVera: The hunter's laser rifle, Betsy.
* LargeHam: Leatherhead has moments of this when he's talking to the hunter
* LaserHallway: The hunter sets one up in the sewers
* MyGodWhatHaveIDone: Leatherhead says this almost word for word when he [[spoiler: attacks Michelangelo in a fit of uncontrollable rage, leaving him unconscious and fearing him badly hurt/dead. Don't worry though; Mikey was fine.]]
* MythologyGag:
** Leatherhead's new home resembles the Turtle's lair from [[Film/TeenageMutantNinjaTurtlesIITheSecretOfTheOoze the second film]].
** During Leatherhead's nightmare, the Shredder has larger blades on his armor that makes him resemble Super Shredder in the same film.
* {{Narrator}}: Leatherhead's first one
* OutrunTheFireball: When Leo's escaping the blast from the land mines
* PleaseKillMeIfItSatisfiesYou: Leatherhead is so grief-stricken by his actions that he's willing and even encouraging to let the hunter kill him... that is, until the hunter mentions hunting down his friends too...
* PutOnABus: Leatherhead moves into a nearby area, where he can deal with his anger in peace.
----