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.
Cast
John Agar
Prof. Clete Ferguson
Lori Nelson
Helen Dobson
John Bromfield
Joe Hayes
Nestor Paiva
Captain Lucas
G
Grandon Rhodes
Jackson Foster
Dave Willock
Lou Gibson
Robert B. Williams
George Johnson
Charles Cane
Police Captain
Loretta Agar
Woman on Boat (uncredited)
Bill Baldwin
Patrol Boat Dispatcher (voice / uncredited)
J
Jere Beery
Photographer (uncredited)
Ricou Browning
The Gill Man (in water) / Lab Technician (uncredited)