Nightmare Fuel / The Rithmatist

  • Wild chalklings in general. Two-dimensional little monsters that swarm over you and eat you alive. Worse, some types can turn people into chalklings.
  • The Forgotten Shadows. Demons that can possess people, and vomit up the aforementioned wild chalklings.
http://tvtropes.org/pmwiki/pmwiki.php/NightmareFuel/TheRithmatist