It is said: "Catch a leprechaun and he will grant you three wishes". Be warned,though, mischief is in the air, and a pot of gold at the end of the rainbow may be just a fool's dream.

I recall two episodes where Samantha and Darrin have a leprechaun around.

S2E27 "The Leprechaun" : Brian O'Brian, who is a friend of Darrin's relatives from Ireland.

S6E27 "If The Shoe Pinches": Tabitha's imaginary friend is really a leprechaun, who likes peanut butter and jelly sandwiches, and chicken soup.

Always fun to watch, especially on Saint Patrick's Day.