Mr. Murphy  is an Irish construction worker and descendant of a founder of the Sons of Erin Society.
On the weekend before St. Patrick's Day 1997, Murphy worked on a restoration job at the Sons of Erin Society Building. He was tasked with clearing out an office but mistakenly found a secret room. Murphy disturbed a mystic circle and freed a Leprechaun. The Leprechaun created a Shillelagh Emanation and demanded his gold. Murphy had no idea what he was talking about. The Leprechaun entrapped him in a little pot. Once the Leprechaun was trapped by the Ghostbusters, Murphy was released along with Mr. O'Toole and Patrick McTavish.