Las ratas no duermen de noche (1973)

Director: Juan Fortuny (as John Fortuny)
Studio: Eurocine, Europrodis, Producciones Miguel Mezquiriz

Alternative Titles:
The Man with the Severed Head
Crimson, the Color of Blood
Crimson, the Color of Terror

Starring: Paul Naschy, Silvia Solar, Olivier Mathot, Evelyne Scott, Claude Boisson, Gilda Arancio, Pierre Biet, Monique Gerard, Alain Hardy, Victor Israel, Richard Kolin, Antonia Lotito, Roberto Mauri, Cesar Ojinaga, Carlos Otero
Description: A mad doctor performs a head transplant on an injured criminal, which results in him being even more dangerous and murderous than before.