Crimson (1973)

aka’s: The Man With The Severed Head/
Las Ratas No Duermen De Noche/
Crimson, The Color Of Blood/
L’ Homme à La Tête Coupée

A mad doctor (Ricardo Palmerola) performs a head transplant on an injured criminal (Paul Naschy), which results in him being even more dangerous and murderous than before. Also stars Silvia Solar and Olivier Mathot. And with Víctor Israel.