This song was sung by Jason and the Pussycats in the episode, Shelf Life. They used to be called Jason and the Argonauts before Tom Sawyer changed them. They are a parody of the Archie comic and TV show, "Josie and the Pussycats."
We're Jason and the Pussycats
We've got guitars and pirate hats
Long swords and treasure maps
North, south, east and west
We got tattoos on our chests... except for Larry
We're battling the monsters
Getting in a fistfight while on shore leave...
[song cut off due to Timmy, Cosmo and Wanda going to the next book.]