Maniac is a 1963 British psychological thriller film directed by Michael Carreras and starring Kerwin Mathews, Nadia Gray and Donald Houston.
Theatrical release poster
Kerwin Mathews was an American actor best known for playing the titular heroes in The 7th Voyage of Sinbad (1958), The Three Worlds of Gulliver (1960), and Jack the Giant Killer (1962).
Mathews as Jack the Giant Killer