RP friends, take note: I do not in fact have an aunt named Flavia.

It's from an episode of Mystery Science Theater 3000 which I watched on Sci-Fi as a kid and rediscovered after I grew up, only to see that it was even better as an adult.

The movie they showed on one of the episodes was called The Thing That Couldn't Die, and it was about a head that wasn't dead. The main character had an aunt named Flavia, who was screechy and had a silly accent. The name just popped into my head when I was making the account on the old guild.