In a tributary of the Amazon, a monster – half-man, half-fish – is captured and placed in a reservoir in a Florida national park to be observed by scientists.
Prof. Clete Ferguson
Helen Dobson
Joe Hayes
Captain Lucas
Jackson Foster
Lou Gibson
George Johnson
Police Captain
Woman on Boat (uncredited)
Patrol Boat Dispatcher (voice / uncredited)
Photographer (uncredited)
The Gill Man (in water) / Lab Technician (uncredited)
Miss Abbott (uncredited)
Cop (uncredited)
Jennings (uncredited)
Skipper (uncredited)
Cop (uncredited)
Pete (uncredited)
Mac - Spotlight Party Leader (uncredited)
The Gill Man (on land) / Marineland Diver (uncredited)
Diver (uncredited)
Charlie (uncredited)
Newscaster (uncredited)
Police Announcer (uncredited)
Dr. McCuller (uncredited)
Girl in Convertible
Search Party Member (uncredited)
Policeman (uncredited)
Joe (uncredited)
Man at Tank (uncredited)
