After Victor Frankenstein brings his dog, Sparky, back to life, a few other kids in his school get the idea to perform their own "mad scientist" experiments. One changes a girl's cat into a half bat monster, another has a giant Gamera-sized turtle, and another has evil Sea Monkeys. And it's up to Sparky to help but things right and protect the town.
There were three animated horror movies released around the same time-- this, Hotel Transylvania and ParaNorman. This goes right in the middle in terms of entertainment valley. This animated feature is very different than the original live-action Frankenweenie short that started Tim Burton's career.