The Monster That Challenged the World (1957)

(Lt. Cmdr. John 'Twill' Twillinger)

(Gail MacKenzie)

(Dr. Jess Rogers)

(Jody Simms)

(Dr. Tad Johns)

(Lt. Robert 'Clem' Clemens)

(Sheriff Josh Peters)

(Sandy MacKenzie)

(Connie Blake)

(Seaman Fred Johnson)

(Sally)

(George Blake (lab assistant))

(Mrs. Simms)

(Lewis Clark Dobbs)

(Seaman Wyatt (Radioman))

(Seaman Morty Beatty)

(Monster Victim)

(Deputy Larry)

(Admiral Greenhouse)

(Deputy Scotty)

(Other Lock Watchman)

(Boy with Morty's Cap)

(Coroner Nate Brown)

(Gatekeeper)

(Patterson)

(Watchman at Lock 57)

(Seaman Howard Sanders)

(Davis - Resort Owner)

(Captain Masters)

(Deputy Brewer)

(Clarke)