One night, a meteorite crashes into the zoo and releases a virus that turns the animals into strange and funny drooling zombie mutants. Gracie, a strange young wolf, tries to find her missing relatives, and a rough and tough mountain lion helps her in her search. They must devise a plan to return all the animals to normal. Teaming up with a motley crew of survivors (Xavier the movie-obsessed lemur, Frieda the fiery capybara, Ash the ironic giraffe, and Felix the treacherous monkey), they embark on a dangerous journey to save the zoo and defeat Rabbit Zero. The crazy mutant king intends to spread the virus beyond the zoo's walls. Welcome to...a night of terror at the zoo!