What do Mojo Jojo, Him, Fuzy Lumpkins, and the Gangreen Gang have in common? They're all major party poopers. That's what the Girls discover when they throw a come-as-your-favorite-villain costume party - and the real villains decide to crash! Now it's Girls vs. villains - in their own backyard! It's their toughest challenge yet. Can the Girls save the day...and themselves?