Ramona Nowitzki

Ramona Nowitzki is a graduate student at Caltech and a huge fan of Sheldon's work. She only appears in The Cooper-Nowitzki Theorem.

She meets Sheldon personally in the cafeteria and arranges to have dinner with him in his apartment. Where other people might be worried about such behavior being reminiscent of stalking, Sheldon reacts positively to Ramona by appreciating the fact that he's getting a free dinner.

She keeps "helping" Sheldon by arranging suitable working conditions for him, such as getting breakfast for him at the cafeteria and giving him footrubs. Unfortunately for Sheldon, she overdoes her insistence that Sheldon dedicate his time solely for work, depriving him of his favorite hobbies such as playing games, watching TV and going for paintball with the guys. Even more unfortunately for Sheldon, he can't seem to get rid of her, especially when she settles herself in his apartment. At times, she appears very suddenly and stalks around the apartment staring at people like the T-X terminator from ''Terminator 3: Rise of the Machines. ''

Ramona proves to be irritating for the entire group, especially when she assumes that Penny likes Sheldon. She makes it difficult for anyone to communicate with him and scares them away.

Eventually, Sheldon solves the problem he's been working on. Enthustiatic about his solution, he asks Ramona to how to can reward her for all her help. But when she asks for him to share credit with her and name the theorem "Cooper-Nowitzki", he finally kicks her out of the apartment, confirming the suspicion that she befriended him so as to claim credit for his work and she was never seen again after that.