The 'House' alum has signed on for the series regular role of DC Comics big bad Reign.

Supergirl has found its new big bad for season three.

Odette Annable has joined the CW superhero drama in the series regular role of villain Reign, The Hollywood Reporter has learned.

Reign will be introduced as part of the show's interpretation of the famed World Killer storyline from the DC Comics.

First appearing in the Supergirl comics in March 2012, Reign is one of several Worldkillers — bloodthirsty, powerful monsters that were created by Zor-El. Like Supergirl, Reign boasts superhuman strength and speed as well as the ability to fly. The Supergirl series teased the introduction of Reign in its second-season finale.

"Greg [Berlanti] and I have wanted to work with Odette for years," executive producer Andrew Kreisberg said Wednesday in a statement. "We are beyond excited to have her join our cast in the scary, powerful and heartbreaking role of Reign."

Annable joins a cast that includes Melissa Benoist as Supergirl, Mehcad Brooks, Chyler Leigh, Jeremy Jordan, David Harewood, Chris Wood and recently promoted season-three series regular Katie McGrath.

For Annable, the series regular role comes after the cancellation of Jason Katims' CBS medical drama Pure Genius, on which she starred. Her other TV credits include Astronauts Wives Club, Banshee, House, Breaking In and Cloverfield. She is repped by UTA and Untitled Entertainment.

Supergirl returns this fall for season three on The CW.