Kathy Bates has joined the cast of 'American Horror Story'.

The 'Misery' actress will star in the third season of the show as the frenemy of Jessica Lange's character and creator Ryan Murphy promises she will be a ''bad, bad woman''.

He said: ''Oh, Kathy's never [played] someone this bad. Her [character] is a bad, bad woman! (The character is) five times worse than [her] 'Misery' character -- which is why she liked it. When I pitched this to Kathy, her mouth was drop-jawed because what I was pitching actually happened. It's a true event ... You'll see. It's some good stuff.''

Kathy revealed late last year she was looking forward to returning to work after taking time off to undergo a double mastectomy following her breast cancer diagnosis.

She said: ''After much consideration, I underwent a double mastectomy. Luckily, I don't have to undergo radiation or chemo. My family call me Kat because I always land on my feet and thankfully this is no exception.''

''My doctors have assured me I'm going to be around for a long time. I'm looking forward to getting back to work doing what I love.''