Ernie Hudson cast as Ursula's father on 'Once Upon a Time'

Ernie Hudson is trading in his proton pack for a trident, as the actor has been cast as Poseidon in Once Upon a Time, EW has confirmed.

Hudson will play the Greek deity and legendary ruler of the sea Poseidon. But the character will have another role in the Once mythology—he will also be the father to Merrin Dungey’s Ursula.

Hudson will appear on the show’s 15th episode when the show’s fourth season returns in 2015. JoAnna Garcia Swisher will reprise her role as Ariel in the episode.

For more on what’s to come from Once Upon a Time, read EW‘s interview with the show’s executive producers or catch up with a recap of the show’s midseason finale.