Piru
- For the town in California, see Piru, California.
The Piru is a minor evil spirit or Demon in Finnish mythology. In Folklore the Piru often features as a nasty spirit of the forest with which a wise-aleck either wins or loses a battle of wits, giving or receiving a Forfeit in return. The Devil is often referred to as Pääpiru, literally "Headpiru".