Niki's Orderly
Lawrence Watkins
Chief of Police
reporter Virgil Whitaker
John C. Allyn
Hughie Sprague
Chuck Haskins
Mike Forrester
George Dunlap
Hotel Clerk
Newell Morse
Dudley Stone
Sergeant McLeash
Warren
Greg Haywood
Truman Hardy
Windy
Charlie
Skinner
Charlie Rickenbacker
Kipp
Professor Caligostro
Patsy
Johnson
Niagara Clerk
John J. Oldham
Charles B. Horsley
Dr. Carver
Speed
Steve Wilson
Muirhead
Professor (archive footage) (uncredited)
Himself