Craze (1974)
Plot: Neal Mottram is a high-strung antiques dealer in London with a deadly secret hidden in his basement: a large, multi-armed African idol named Chuku. Believing that the idol grants him wealth and success in exchange for human blood, Neal begins a spree of ritualistic sacrifices. His victims include associates, acquaintances, and even his own elderly aunt, whom he "scares to death" while wearing a grotesque mask to secure her inheritance. As the bodies pile up and police inspectors begin to close in, Neal’s descent into madness accelerates, leading him to wonder if the idol is truly a god or if he has simply been lost in a murderous delusion.