Characters played by Boris Karloff
Dr. Leon Kravaal
Characters played by Roger Pryor
Dr. Tim Mason
Characters played by Jo Ann Sayers
Judith Blair
Characters played by Stanley Brown
Bob Adams
Characters played by John Dilson
John Hawthorne
Characters played by Hal Taliaferro
Sheriff Stanton
Characters played by Byron Foulger
Dr. Bassett
Characters played by Charles Trowbridge
Dr. Harvey
Characters played by Ernie Adams
Pete Daggett