Robert Patrick returning to 'True Blood' as Season 6 regular

Robert Patrick has signed on as a series regular for "True Blood's" sixth season, reports Deadline.

As Alcide's (Joe Manganiello) father, the werewolf and disgraced former packmaster Jackson Herveaux, Patrick appeared in three episodes of Season 5 -- including the pivotal finale in which Alcide declares himself the new packmaster.

The "Terminator 2" actor's schedule opened up when ABC nixed a back-nine pickup of "Last Resort," on Patrick which co-stars as the volatile Chief of Boat Prosser.

"True Blood" returns to HBO in summer 2013.