The Bowery Boys--Slip, Sach, Bobby, Whitey & Chuck--start their own exterminating service, and get a job which takes them to a spooky old abandoned mansion in the middle of the night. Meeting up with pal Gabe and his new French bride, the boys are tormented by mad scientists who try to convince them the place is haunted and then kidnap Sach in order to place his brain inside a gorilla.

The entertainment duo Mitchell & Petrillo, en route to a USO show for troops in Guam, fall out of their plane and end up on the jungle island of Cola Cola, where the mad scientist Dr. Zabor is conducting evolutionary experiments.

Deep in the Northern California woods, in the heart of the notorious Emerald Triangle, lies a remote cabin. The residents struggle to fight off the repeated attacks and abductions by mysterious creatures that have plagued them for years. When a local pot farmer is caught up with a wayward group of campers the situation quickly escalates into total carnage.