Monster A Go-Go 1965

Synopsis:

American astronaut Frank Douglas mysteriously disappears from his spacecraft as it parachutes to Earth. He is apparently replaced by or turned into a large, radioactive, humanoid monster. A team of scientists and military men attempt to capture the monster.

Directed by: Bill Rebane & Herschell Gordon Lewis
Written by: Bill Rebane & Jeff Smith & Dok Stanford
Runtime: 70 minutes
Tagline: An astronaut went up- a "guess-what" came down!
Cast:
Henry Hite
Henry Hite
Frank Douglas as a Monster 
Phil Morton
Phil Morton
Col. Steve Connors 
Lois Brooks
Lois Brooks
Dr. Nora Kramer (unconfirmed) 
Rork Stevens
Rork Stevens
 
Robert Simons
Robert Simons
 
Peter M. Thompson
Peter M. Thompson
Dr. Chris Manning