The Scaring of the Green

When the Ghostbusters are arrested for accidentally/nearly killing the mayors wife (actually just frying her dress off) the deputy police chief, O'Malley, makes a deal with them to get them out of their predicament. According to him, an ancestor of his stole a pot of gold from a leprechaun, which caused the leprechaun to curse the O'Malley family line. Every St. Patricks Day, during a full moon, a Bog Hound rises up and seeks out the head of the O'Malley clan, which is the deputy police chief, to carry them off. The only thing that can stop the Hound, is a Four-Leaf Clover. The Ghostbusters search the city for a four-leap clover, while Egon goes alone to try and catch the Bog Hound with 'science'. However, while Egon finds the Bog Hound at the New York City Zoo, he finds out that his proton pack is uncharged, leaving him defenseless as the Hound chases him down. After getting treed by the Hound, which is full of lions, tigers and leopards, Egon barely escapes by tricking the Hound, and then tries to regroup with the others. Peter eventually finds a Four-Leaf Clover, but Slimer eats it. The Ghostbusters have no choice but to play bodyguard to Deputy Chief O'Malley in order to find and capture the Bog Hound. When the Hound attacks O'Malley at the St. Patrick's Day parade, the Ghostbusters try to stop it, only to get their proton packs damaged in the fight. Peter distracts the Hound with a fake Four-Leaf Clover (which he didn't know was plastic) and leads it into a ghost trap laid by Egon. The Ghostbusters are then proclaimed 'Honorary Irishmen' by the St. Patricks Day committee.