The Star Trek Encyclopedia (4th ed., vol. 1, p. 460) described the leprechaun as a "mischievous homunculus" from the mythology of Earth's Irish people. This diminutive human-like creature was "said to know the location of a great treasure and to have a supernatural ability to grant wishes."
The first draft script of DS9: "If Wishes Were Horses" featured a leprechaun. In the script's stage directions, this character was initially described as "a tiny man, complete with green suit, three-pointed hat, large buckled shoes and carrot red hair... in short a classic leprechaun." Ultimately, however, this character was changed to Rumpelstiltskin. The alteration was made after Colm Meaney objected, commenting, "Using caricatures or clichés of any nation is not something Star Trek is or should be into." (Star Trek: Deep Space Nine Companion) The leprechaun was replaced with Rumpelstiltskin by the time the third draft of the script was issued.