On screen
Cast
15 credited performers
Don Terry
Larry Kent
Gwen Gaze
Toni Morrell
Walter Miller
Carter 'The Shark' Collins
Artwork unavailable
George Rosener
Capt. Samuel Cuttle
Grant Withers
Roderick Gridley
Hobart Bosworth
Dr. X
Artwork unavailable
Sandra Karina
Nurse Zanya
Artwork unavailable
P.J. Kelly
Prof. Gault
Yakima Canutt
Dreer (Mole-Men Leader)
William Farnum
George Brennan Westmore (Editor)
Joe Caits
Saltwater Jerry [Chs.1,4-7,13-15]
Colin Campbell
Hawkins (the Butler) [Chs. 1-3]
Dave O'Brien
Det. Jameson [Chs. 4-7]
William Royle
Paul Thorndyke [Ch.1]
Warner Richmond
Capt. Tom Stanton, alias Capt. Tom Faxton [Ch.1]