The Harley Troop is an army of various creatures lead by Harley B. Koopa. While they are not allied with the Koopa Troop or the Boo Troop, they are not enemies with them and will never attack them. While Bowser wants to take over the Mushroom Kingdom and King Boo wants to take over Sarasaland, Harley set his sights on the entire Mushroom World.