Storyline:
The blood of a primitive fish exposed to gamma rays causes a benign research professor to regress to an ape-like, bloodthirsty prehistoric hominid.

Cast:

Arthur Franz Professor Donald Blake

Joanna Moore Madeline Howard

Judson Pratt Police Lt. Mike Stevens

Nancy Walters Sylvia Lockwood

Troy Donahue Jimmy Flanders

Phil Harvey Police Sgt. Powell

Helen Westcott Nurse Molly Riordan

Whit Bissell Dr. Oliver Cole

Ross Elliott Police Sgt. Eddie Daniels

Louis Cavalier Student (uncredited)

Richard H. Cutting Tom Edwards - Forest Ranger (uncredited)

Eddie Parker Donald as a Monster (uncredited)

Hank Patterson Townsend - Night Watchman (uncredited)

Ronnie Rondell Jr. Student (uncredited)

Alexander Lockwood Professor Gilbert Howard

Medium: Original DVD,

Location: On the Shelf - The Classic Sci-fi Ultimate Collection

Loaned: No

Aspect ratio: 2.39:1