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Being Human's Sam Witwer has signed up for Once Upon a Time.
The actor will recur as Jacob, an evil warden at a mental institution who "takes pleasure in tormenting his most disturbed and helpless patients" (via Deadline).
Hank Harris - who has appeared in The Man in the High Castle and Salem - will play one of Jacob's patients Nathaniel.
Once Upon a Time recently celebrated its milestone 100th episode, as the main characters look to rescue Hook from the Underworld.
Will Scarlet actor Michael Socha, who was dropped as a series regular, told Digital Spy that he felt "quite redundant" on the show but suggested that he'd be open to returning.
Aside from Being Human, Witwer played Davis Bloome / Doomsday in the eighth season of Smallville.
