History
As part of his quest to make himself look like the ultimate hero of Asgard, Loki sent his adoptive brother Thor to Nornheim, land of the Rock Trolls, where Ulik battled with Thor. Contrary to his plans, Loki was forced to aid his brother in activating the Troll equivalent of the Bifrost Bridge, Frostgrinder, in order to escape, realizing that Mangog was too powerful for him to defeat on his own. Thor defeated Ulik prior to activating Frostgrinder.[1]