In the book Coraline by Neil Gaiman, Mr. Bobo is the man who lives in the flat above Coraline. Although Coraline meets him very early in the book, she never actually thinks about asking his name. Prior to learning his name, she only thought of him as the "crazy old man upstairs." He used to be in the circus, according to Miss Spink, and comes from a "fine old circus family" from one of the Eastern European nations. Coraline is delighted to know his name. It's such a fun name to say that she would have said it more often had she known it sooner.
Mr. Bobo tells Coraline that he has trained mice—or mice that he is trying to train—as part of a musical mice circus. However, they can't seem to coordinate their music. Coraline wonders if there really is a mice circus since she hasn't seen the mice. Mr. Bobo makes strange statements and passes along a message from the mice that she shouldn't go through the door.
In the movie version of Coraline, Mr. Bobo's name is Mr. Bobinsky.