TNT

The Catwoman from Channel Six - S2-E12

Plot hole: April is transformed into a Catwoman by a teleportation accident. Shredder puts a mind control collar on her, and she attacks the turtles. The turtles manage to remove the collar, and the fight ends. Shortly afterwards, April returns to her normal form, without any explanation.

TNT

Invasion of the Punk Frogs - S2-E8

Stupidity: Shredder uses a holographic projector to appear as a normal person. He could have just taken off his armor.

TNT

Invasion of the Punk Frogs - S2-E8

Plot hole: Shredder meets the frogs for the first time and gives them clothes using the holographic projector. The frogs continue to wear the same clothes for the rest of the episode, even without Shredder being around.

TNT

New York's Shiniest - S2-E10

Continuity mistake: The turtle van falls on a bridge, the turtles escape swimming. Shortly afterwards, April appears driving the van, looking for the turtles.

TNT