children shouldn't play with dead things (1973)

aka Cemetery of the Dead. Things from the Dead. Zombie Graveyard.
"You should have stuck to the clown act."
A couple of actors play a prank on some friends, pretending to dig up a corpse and perform a satanic ritual to resurrect the dead. Unfortunately for everyone their spells work!
Would be comedy that is far to talky for its own good, taking far too long to get to the chomping.

black christmas (1974)

AKA Silent Night, Evil Night. Stranger in the House.
"No Claire, that's the Mormon Tabernacle Choir doing their annual obscene phone call!"
It's Christmas break, and in a Canadian sorority the sisters are making their holiday plans. But they are being plagued by a deep breather on the phone, and when one of their number disappears they are set on edge. Especially when the police don't express much concern. Until they discover the body of a 13-year-old girl in the park and the students start being attacked. Let the stalking begin...
Starring Olivia Hussey, Margot Kidder, and John Saxon, this is a low key but effective thriller.