Cast: James Franciscus (Tuck Kirby); Gila Golan (Theresa Juanita 'T.J.' Breckenridge); Richard Carlson (Champ Connors); Laurence Naismith (Prof. Horace Bromley); Freda Jackson (Tia Zorina); Gustavo Rojo (Carlos dos Orsos); Dennis Kilbane (Rowdy); Mario De Barros (Bean); Curtis Arden (Lope); Jose Burgos (The Dwarf)

Directed by Jim O'Connolly; Written by William Bast (as William E. Bast); Julian More; (additional material) Willis H. O'Brien (uncredited) (story Valley of the Mist); Cinematography by Erwin Hillier; Original music by Jerome Moross; Film Editing by Henry Richardson; Produced by Charles H. Schneer, Ray Harryhausen (associate); Wardrobe Supervisor: John Furniss; Production Manager: Miguel Gil; Continuity: Gladys Goldsmith; Visual Effects: Ray Harryhausen; Camera Operator: Alec Mills; Art Director: Gil Parrondo; Production Supervisor: Luis Roberts; Sound: Malcolm Stewart; Assistant Director: Pedro Vidal