'Cosby Show' Alum Phylicia Rashad Cast As Beth Pearson's Mom On 'This Is Us'

This Is Us has hired a big name for the role of Randall Pearson's mother-in-law. The Cosby Show matriarch Phylicia Rashad has been cast as Beth Pearson's (Susan Kelechi Watson) mom, Carol, EW.com reports. Beth's mom will first appear in the second half of the NBC hit drama's third season in an episode that focuses on the backstory of the future wife of Randall.

Rashad is best known for playing attorney and mom of five Claire Huxtable on the long-running NBC sitcom The Cosby Show, which she starred in opposite Bill Cosby from 1984 to 1992. The Tony-winning actress reunited with Cosby for his self-titled CBS comedy from 1996 to 2000, once again playing his wife. In more recent years, Phylicia Rashad has recurred as Diana Dubois on Empire and is set to star in OWN's upcoming drama David Makes Man.

Last month, Susan Kelechi Watson told TV Line her character's backstory would be showcased in Episode 13 of this season.

"We have a really great new writer Eboni Freeman, [who is] the main writer on it, and some of it is her story, very personal to her," the This Is Us star said. "They found a way to create this really beautiful backstory, and a beginning of a resolution of Beth starting to get back on her footing again. And then we have some amazing surprises in it. It's going to be a really powerful episode."

While This Is Us fans have already met Beth's cousin Zoey (Melanie Liburd), Kelechi Watson previously told the Los Angles Times that viewers would also learn a lot more about Beth's extended family in Season 3.

"That's something we're going to learn about in Season 3 — that she has a Jamaican background," the This Is Us star told the Times. "Her mom is still alive, her dad isn't, obviously. She has sisters and comes from a big family. Seeing how that plays into her life, who does she go to for advice and help outside of the Pearson clan...she's like a slow-peeling onion."

Phylicia Rashad is the latest in an impressive list of guest stars for This Is Us. The NBC drama has already featured guest roles for familiar stars such as Katey Sagal, Sylvester Stallone, Jane Kaczmarek, Denis O'Hare, Seth Meyers, Katie Couric, Ron Howard, Garret Morris, Gerald McRaney, Debra Jo Rupp, and Griffin Dunne.

This Is Us returns with its winter premiere on Tuesday, Jan. 15 at 9 p.m. on NBC.