Robert Patrick made his True Blood debut last season as Alcide's father in a three-episode arc. Patrick, best known for playing T-1000 in Terminator 2, will return as a series regular in next year's sixth season.
Patrick played Jackson Herveaux, Alcide's estranged werewolf father. He was once the pack leader, but was kicked out for stealing money. He also was hooked on V, something that Alcide desperately disapproved of. After being kicked out of the pack himself, Alcide returns to his father, and they slowly rebuild their relationship.
True Blood season six is expected to return to HBO this summer.