You know what really freaked me out was Creepshow, when the critter in the cage bit off half that guys face--maybe that's why I'm so squeamish around blood.
There was one I saw while in college...some weird critters were turning folks into zombies...their method for doing that was to go in through people's mouths. At the end, only one zombie was left...a dog.
The hero and his girly have finished vanquishing the zombies, when the girly bends down to pet the dog...and the critter that turned folks into zombies jumps into her mouth.
Since then, I refuse to let any dog lick my face.