Critter

 Growing up, my friend, J, lived in a house full of paranormal activity.

One of the strange entities that made frequent appearances lived in the downstairs bathroom, right across from the side door that leads outside.

She explained that the creature very strongly resembled the aliens from that movie in the 80's "Critters".

That bathroom door was always latched shut, aside from a sliver of a gap to allow their cats to slip in to use the litter box.

J said the cats were never harmed. But wheb she would come in through the side door at night, she would always see the creature peering out through the door at her.

It was about a foot tall, and had red eyes and a smiling mouth full of sharp teeth. 

It never left the bathroom, but that wouldn't stop J from bolting up the stairs every time.