The Brain The Wouldn't Die(1962)
Brilliant but borderline psychotic surgeon does secretive, experimental work with limb transplants and tissue rejection drugs, much to the chagrin of his surgeon-father. When he crashes his car and his fiancee is decapitated, his research - far from complete - is put to the test. His focus then becomes finding an appropriate donor body to make his fiancee whole, while the current and failed experiments in his basement laboratory grow restless.