Redcap

Redcaps were evil murderous fey with an insatiable bloodlust. They appeared in the Feywild or at places where creatures acted on a deep desire for bloodshed.

Redcaps needed to kill constantly in order to continue existing. Their pointed red hats needed to remain soaked in fresh blood, which had to be replenished at least once every three days, otherwise the redcap would simply disappear, a fact they are entirely aware of. Their scythe and boots are spawned naturally with them.

Rumors & Legends
In halfling fairy tales, redcaps were said to be former halflings cursed as punishment for betrayal, but these were just stories and nothing more.