Psychomania

Psychomania (U.S. title:The Death Wheelers) is a 1973 British outlaw biker horror film directed by Don Sharp, and starring Nicky Henson, Beryl Reid, George Sanders (in his final film), and Robert Hardy.

The plot follows the adolescent leader of a biker gang, who has started practicing black magic. After meeting the Frog God, which his mother worships, the leader commits suicide on his 18th birthday. His mother resurrects him as one of the undead, and the process grants superhuman abilities to the boy. He proceeds to turn most of his gang into fellow undead, but his mother petrifies them all in a magic ritual.