Melissa McCarthy, Kathy Bates and Billy Gardell

American Horror Story: Coven's Kathy Bates is bringing misery to CBS's Mike & Molly on the March 17 episode when she guest stars as Kay, an old buddy of Molly's grouchy mother-in-law, Peggy. Kay has a fun-loving, freewheeling, very un-Peggy-like personality that makes Molly (Melissa McCarthy) her biggest fan. But Peggy quickly grows resentful of Molly and Kay's ­nascent friendship.

"Kay's an exciting, well-traveled, well-read adventurer," executive producer Al Higgins says. "Molly sees her as a kindred spirit who's lived the life she's just begun living since she quit her teaching job. But Peggy is a tad territorial over Kay. She doesn't exactly have many friends, and she thinks Molly is trying to steal one of the few she's got left."

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