The Dire Bear only has one role in the story in the O Canada quest where three of them killed a Canadian and the New Kid is tasked with slaying it after speaking to the Earl of Winnipeg. Outside of that, they are random encounters on the world map of Canada.
The Dire Bear farts on the New Kid or his buddy and if it isn't blocked, inflicts Grossed Out as well as heavy damage.
The Dire Bear throws 4 balls at both the new kid and his buddy. Inflicts Burning if not blocked.
The Dire Bear shoots lasers out of its eyes at the New Kid or his buddy, inflicting Ability Down if not blocked.
The Dire Bear cub calls an adult Dire Bear into battle (Only available to Dire Bear cubs).