Who is roommate on transformers 2?

There is no character named "Roommate" in Transformers: Revenge of the Fallen (2009). Perhaps you are thinking of a different character from the film?

To help me understand better, could you please tell me:

* What is the character's role in the film?

* What does the character look like?

* Any other details you remember about the character?

With more information, I can help you identify the character you're thinking of.