The Ghoulies are unkillable: In their third installment, the little monsters turn another institution of American life upside down – a university campus – and once again create maximum chaos. All hell breaks loose on the college campus. Two rival fraternities try to outdo each other with their pranks. By chance, the Ghoulies are reanimated, and they cause even more mayhem. Principal Ragnar manages to subdue the creatures, hoping to use them to take revenge on the students. The next pranks target the students, but the Ghoulies don't even shy away from murder. When Skip's girlfriend Erin is about to be sacrificed, that's the last straw. Skip rescues his girl and flushes the Ghoulies, along with Professor Ragnar, down the toilet.