For the japanese manga of the same name see Ratman manga
Two models, Marlis and Peggy, are on a Caribbean Island for a photo shooting. One night Peggy is found dead and her body seems eaten by rats.The victims sister, Terry, arrives on the island and helped by a mystery novel writer met at the airport starts to investigate. Meanwhile Marlis and the photographer find other corpses in the jungle. Searching for an help they stopped at an isolated house just to discover that the landlord is a scientist who created a ferocious mutant halfape, half rat. ........
Source: Wikipedia