The characters of Tokka and Rahzar fall under this. Remember the fights they had with the heroes? Remember how they are essentially defeated by being tricked/force-fed into eating anti-mutagen changing them back to normal? Well, now take those battles into consideration when you remember that they're babies.
It's even worse when you remember that Shredder pretty much sent them out on a destructive rampage by tricking them into thinking that's what "playing" means. In other words, Shredder pretty much brainwashed two innocent children (albeit said children are a mutated wolf and snapping turtle) into endangering themselves and others for "fun".
They're not actually babies, Professor Perry sabotaged the mutagen that created them to make them less intelligent (and therefore less of a threat) and the final shot of them returned to normal shows that both Tokka and Rahzar were full grown.
Which provides another type of Fridge Horror as there is now a full-grown WOLF in the middle of a crowded nightclub of people!!
But they did act like children... which means that Professor Perry probably made Tokka and Rahzar mentally handicapped!
No, the mutagen enhances intelligence, Splinter explained it in the first movie. Professor Perry's sabotage involved making Tokka and Rahzar bigger than the turtles but not as intelligent. They are clearly smarter than the average snapping turtle and wolf, but not as smart as a human adult.
At the end they show the two un-mutated, and while its hard to tell Tokka's age (But probably older given how long it takes most turtles and tortoises to grow to that size) Rahzar is definitely immature (if not an actual puppy).
Vanilla Ice's rap. It strains credibility that he could just come up with a full song on the spot and that his band could follow, right? Except that in the context of the movie he was probably freestyling, and his band was just playing generic accompaniment that they planned ahead of time so he could freestyle. He might have even planned some improvisation before the turtles came in, and he just took advantage of the situation. Being able to improvise and freestyle on the fly is considered a vital skill for any aspiring rapper.
Some fans have complained that Shredder was defeated too easily after becoming the Super Shredder, but others have observed that this may be justified by him not having fully recovered from his beating in the previous film. From the moment he returns to the Foot Clan, Shredder is never shown actually fighting anyone, creating the idea that he is relying on his reputation to hide the fact that he is still weak and couldn't even survive such a confrontation. Assuming that Shredder is already weak and hiding it, his use of the mutagen on himself could have disrupted his physiology to such an extent that the damage caused by the collapsing pier was just too much for his body to take after everything else he'd been through.
Some Fridge Squick to consider: Shredder had been inside of that garbage pile for an unspecified amount of time, making it likely that his wounds from Leonardo and getting crushed inside the garbage truck got infected. Him drinking the Mutagen could've accelerated whatever infections were running through his bloodstream, which combined with his altered physiology (and getting blown out of the windows at the dance club) could easily contribute to his self-inflicted demise.
Furthermore, Perry mentioned earlier that he sabotaged the Foot's Ooze to make Tokka and Rahzar dumber and less dangerous than they would have been otherwise. No doubt Super Shredder suffered from this as well, which would explain why he didn't think twice about destroying the docks to get the Turtles.
Why a wolf and a snapping turtle instead of a rhino and a warthog?note Besides rights issues. They're lighter and easier to transport.
Where is Casey Jones during all of this? While its a bit strange that he's never mentioned even once in the film, his absence makes perfect sense when you remember that he humiliated Tatsu and, as far as anyone knows at first, Killed Shredder. Anyone would skip town until the third movie, under those circumstances.
