The Shadowlurker is a Creepypasta-turned-meme creature.
The Shadowlurker was said to hide in the darkness of a room. It has large sunken eyes, and a huge creepy smile (All the creepypastas seem to have creepy smiles except for Herobrine).
The meme of it is its face, with quotes usally like "Legs hanging of the edge of your bed? It's mine now" or "It's late. You should go to bed. That is, if you get there."