Night of the Bloody Apes (1969)

A desperate surgeon resorts to an unorthodox solution to save his gravely ill son by transplanting an ape's heart into him. However, the procedure unleashes a nightmarish transformation, leading to violent and gruesome outcomes. As the boy's condition deteriorates, chaos ensues, and the once-hopeful experiment spirals into a horrifying tale of madness and terror. The blend of medical ambition and primal instincts reveals the dark consequences of playing god, resulting in a grim exploration of the limits of science and the monstrous potential lurking within.