In season 6 of The Big Bang Theory, Raj spends a night out with the girls while Kaley Cuoco's Penny character showcases what the guys are missing. Melissa Rauch's Bernadette shocked viewers with a new outfit. Let's look back on Rauch stealing the scene in The Santa Simulation episode. Fans raved about Rauch's dress and appearance. Rauch's role was initially for one episode, but she became a permanent cast member. Mayim Bialik was hesitant about Amy's edgier appearance. Bialik wanted to stay true to Amy's character.