New cat, who appears to be a Himalayan, is one of Dr. Calico's cats. While there is no evidence that suggets he's going to be taking over the other cat's roll (who's labled as "senior cat" on the IMDb page), it's possible that he is. The first time he appears on screen, the senior cat mentions to him (while on their way to Bolt's trailer to mess with him) how Bolt believes everything is real, and tells him he isn't ready for the evil laugh when he tries to do so.