The Brain That Wouldn't Die (1962)
ALIVE... WITHOUT A BODY... FED BY AN UNSPEAKABLE HORROR FROM HELL!
A doctor experimenting with transplant techniques keeps his girlfriend's head alive when she is decapitated in a car crash, then goes hunting for a new body.
Good MST3K episode too.
Apparently in the public domain from day one due to a flawed copyright notice, so it's on all the streamers, including Internet Archive & Wikiflix (if y'all want to avoid ads & data surveillance).
https://wikiflix.toolforge.org/#/entry/129074
Ooh, originally released as a double feature with Invasion of the Star Creatures, one of #Monsterdon's most derided features!
A classic B-movie with a pulpy premise, some silliness, a bit of sexual innuendo, and quite a disturbing undertone.
The Brain That Wouldn't Die should be available for streaming on Tubi.