A half-shark, half-octopus creature created for the military, creates a whole lot of terror in Mexico while a scientist who helped create it tries to capture/kill it.

An American scientist creates a half-pterodactyl, half-barracuda creature, Pteracuda, which inevitably escapes, leaving the Sharktopus to stop it.

When a mad scientist mixes the genes of a killer whale and a wolf, it creates the Whalewolf, and it's up to Sharktopus to stop it.