Lotor uses the radiation on Planet Geo to mutate an egg. The egg hatches into a giant antimatter-spewing lizard called Dominus, and wrecks havoc on the planet and the team. He eats a moon with antimatter and falls asleep. The team come up with a plan to take down Dominus by making it attack Haggar's ship. This causes Haggar to shrink Dominus back down again.