While Cosmo was in Little Ireland explaining the holiday of Leprechannukah to his family, he was dressed up as a leprechaun himself, and was spotted and captured by Denzel Crocker whom had recently undergone a change of vocation and was now hunting leprechauns. In exchange for not exposing him, Cosmo cut a deal with Crocker and gave him a pot of gold, which Crocker took off with. Since Fairies cannot create money, Wanda asked Cosmo where he got it and he revealed that he had taken it from a trio of leprechauns known as the McPunchy brothers.
The McPunchies quickly appeared to retake their gold, and when they found out Cosmo had given it away, they took Wanda and Poof captive until Timmy and Cosmo could return it. In the end, the McPunchies explain that they didn't really care about getting the gold back -- in reality, they just wanted the pot (that the gold was stored in) back. The brothers explain that the pot's an old family heirloom (and, at least judging from Big Dave's reaction, has a lot of sentimental value to the brothers).
- Big Dave - Big Dave is the leader of the McPunchies leprechaun clan. He is bigger than his brothers, and drives a motorcycle.
- Lucky - Lucky has a red beard and white skin, and is shorter than Big Dave.
- Greeny - Greeny has a green beard and skin, and has a tattoo of a four leaf clover on his arm.