None popped up in the Compendium.
What did you want them to do in your game? What sort of niche? The 2nd Ed. leprechauns had no attacks, measley hit points and AC, and primarily just turned invisible, used ventriloquism, and stole from the PCs. That's something you could emulate without statting up a full creature.
And some of the creatures they already have could possibly fill the niche you're looking for: gnomes, spriggans, gremlins.