when a group of escaped convict manage to flee to a remote island and they soon find that their new home be inhabit by a strangely menacing doctor ( richard johnson of zombi 2 fame ) and a mad scientist ( joseph cotten ) and his beautiful daughter ( barbara bach ) and a horde of superstitious native . the tribesman say that the doctor have create grotesque half human and half fish creature for evil and secretive purpose . and though at first the prisoner do not believe this and a they disappear and one by one and they begin to change their mind . screamer be a very entertaining mix of mysterious island and humanoid from the deep . there be plenty of gore with really cool decapitation scene and throat tearing to boost . the acting be so so and but the film be fast paced and entertain . give it a look . positive .