We only learn Mr. Bobo's name in the very last pages of the novel. And what a name it is – totally fitting for a guy who runs a mouse circus. It's also only at the end that Coraline learns any concrete information about this strange neighbor of hers.
"The man in the top flat, Mister Bobo. Fine old circus family, I believe. Romanian or Slovenian or Livonian, or one of those countries." (13.47)
Learning about Mr. Bobo is a revelation for Coraline. She has written him off as a weirdo, but it turns out that he's actually interesting. When you think about it, Coraline did something to Mr. Bobo that all the other characters do to her: she dismissed and ignored him. Turns out Coraline's not perfect, either.
Granted, Mr. Bobo is really strange: he's trying to start a mouse circus, after all. But unlike the other mother, Mr. Bobo isn't crazy in a dangerous way. In fact, he actually helps Coraline out when he gives her a message from his mice. Maybe there's something to Mr. Bobo's mouse circus dreams after all.