Miranda Otto has been cast as a series regular in the upcoming Netflix series based on “Chilling Adventures of Sabrina,” Variety has learned.

Otto will play Zelda Spellman, Sabrina’s sterner witch aunt. Proud and devout, Zelda believes there is no greater honor than serving the Dark Lord as a member of the Church of Night. She is the family’s disciplinarian, fiercely protective of Sabrina, and very much Cain to aunt Hilda’s Abel. The role of Zelda was played by Beth Broderick in the multi-camera comedy series “Sabrina the Teenage Witch.”

Otto starred as Eowyn in “The Lord of the Rings: The Two Towers” and the sequel “The Lord of the Rings: The Return of the King.” She has also appeared in films like “The Thin Red Line,” the 2005 version of “War of the Worlds,” and “Annabelle: Creation.” On the TV side, Otto recently appeared in “24: Legacy” for Fox and in Showtime’s “Homeland.”

She is repped by Gersh and Management 360.

Otto joining the series rounds out the Spellman family cast for the new show. Kiernan Shipka was previously cast in the lead role of Sabrina, while Lucy Davis has been cast as Hilda. Chance Perdomo will play Sabrina’s warlock cousin Ambrose. Michelle Gomez has also been cast in the role of Mrs. Wardell, a.k.a. Madam Satan, and Jaz Sinclair has been cast as Sabrina’s best friend Rosalind Walker.

The untitled series based on the Archie Comics character has received a 20-episode, two season order at Netflix. It was originally in development at The CW to serve as a companion series to fellow Archie Comics property “Riverdale.”

The one-hour drama reimagines the origin and adventures of Sabrina as a dark coming-of-age story that traffics in horror, the occult, and witchcraft. The series is described as being tonally in the vein of horror classics like “Rosemary’s Baby” and “The Exorcist,” and will see Sabrina wrestling to reconcile her dual nature as a half-witch, half-mortal while standing against the evil forces that threaten her, her family, and the daylight world humans inhabit.

Roberto Aguirre-Sacasa, chief creative officer of Archie Comics, will serve as writer and executive producer. Lee Toland Krieger, who has directed multiple episodes of “Riverdale,” will direct and executive produce. Greg Berlanti, Sarah Schechter, and Jon Goldwater–all executive producers on “Riverdale”–will also executive produce. Berlanti Productions will produce in association with Warner Bros. TV.