The Deranged Daughter of Daphne Dickensen and the Leftovers from Hell (1984)

A young girl named Nikki Dickensen's mother always sends leftovers for her lunch, which Nikki hates. So one day, after finding her mother Daphne canoodling with a young punk who was actually HER boyfriend, she kills her mother in a rage. Daphne's blood splashes onto the sandwich of leftover tongue and brings it to life.