leprechaun

In Irish folklore, a mischievous elflike creature or fairy who grants wishes or reveals the location of hidden treasure when captured.

A small mischievous elf or spirit in Irish folklore; it is often depicted in literature as a dwarfish bearded old man; — legend tells that if a leprechaun is captured, he will reveal the location of his hidden pot of gold.

One of a race of elves who can reveal hidden treasure to those who catch it

a mischievous elf in Irish folklore