"A small town doctor mistakenly ingests an experimental drug made from the blood of vampire bats which transforms the kindly medic into a bloodthirsty monster."
John Beal
as Dr. Paul Beecher
Coleen Gray
as Carol Butler
Kenneth Tobey
as Buck Donnelly
Lydia Reed
as Betsy Beecher
Dabbs Greer
as Dr. Will Beaumont
Herb Vigran
as Sgt. George Ryan
Paul Brinegar
as Willy Warner
Ann Staunton
as Marion Wilkins
James Griffith
as Henry Winston
Hallene Hill
as Mrs. Carrie Dietz (uncredited)
Raymond Greenleaf
as Autopsy Surgeon (uncredited)
Wood Romoff
as Dr. Matthew J. Campbell (uncredited)
Brad Morrow
as Tommy (uncredited)
Mauritz Hugo
as Joe, the Waiter (uncredited)
Anne O'Neal
as Marion's Housekeeper (uncredited)
Louise Lewis
as Mrs. Miller (uncredited)
Arthur Gardner
as Anesthetist (uncredited)
Natalie Masters
as Ruth (uncredited)
George Selk
as Mr. Spine (uncredited)
Christine Rees
as Jennie (uncredited)
Walter Merrill
as Carl James (uncredited)
Carl Sklover
as Gravedigger (uncredited)
Michael Jeffers
as Bartender (uncredited)
Chet Brandenburg
as Restaurant Patron (uncredited)
Paul Landres
Director
Gerald Fried
Conductor
Donald W. Roberson
Makeup Artist
Carmen Dirigo
Hairstylist
Joel Moss
Sound
Pat Fielder
Story
Charles Althouse
Lyle Cain
Screenplay
Producer
Arnold Laven
Jules V. Levy
Original Music Composer
Jack MacKenzie
Director of Photography
John Faure
Editor
James Dowell Vance
Art Direction
Rudy Butler
Set Decoration
Marty Moss
Assistant Director