Mickey has siblings?

A: Daddy, 'member when we were at DisneyLand?
Me: Disney World
A: Right, right right.  Cinderella's castle had fireworks, that was beautiful.
Me: Sure was
A: Who do you think was making the fireworks?
Me: I don't know buddy, maybe it was magic
A: I think it was little holes in the castle and somebody pushing a button to make the fireworks go out of the holes.
Me: Wow, that's pretty smart buddy, who do you think was pushing the buttons?
A: Well... it wasn't Mickey Mouse because he was on stage.  <LONG PAUSE> Oh, I know!  It was Mickey's brother!!
Me: I didn't know Mickey had a brother.
A: Yes, Mick Mouse.
Me: Oh.