Gunnar was the leader of a band of robotic Vikings whose weapons used freezing blasts. Gunnar, along with is band of robotic vikings were frozen in an iceberg in their own dimension but were released by the meteor that struck Acmetropolis. While on Acmetropolis they attempted to freeze the world so it's easier to take over, starting with Acmetropolis' planetary power generator. The Loonatics battled him and the other vikings in the city. He was deactivated as well as his other minions when Ace kicked him at the planetary power core, restarting all power in the city.