Thread:Jester of chaos/@comment-26868495-20150810030509/@comment-25008763-20150828003848

demons are pretty much portrayed as omnipotent beings that can do anything a god can do (just at a lower scale) - Pennywise takes the form of anything that scares someone : he's appeared as more than just a clown.. his "true" form is actually the ghostlight energy that kills anyone that looks at it.

TLDR version: Pennywise is basically an evil spirit and can do whatever he wants.