In chapter 4 who is Kilpspringer?

Our narrator, Nick, calls Klipspringer "the boarder," because he stays at Gatsby's house so often that he practically lives there.  Though most people at Gatsby's come and go, Klipspringer stays.  He is a minor character, though he later becomes an example of the type of person who befriends Gatsby (you'll see what I mean once you finish the novel).

The only other time the novel mentions Klipspringer is when Nick, Daisy, and Gatsby are at Gatsby's mansion, and Gatsby calls Klipspringer to the room to play the piano for them, thus "setting the mood" for Daisy and Gatsby.  There (at the end of chapter five), Klipspringer seems slightly awkward and taken aback, stuttering about his lack of skills ("I don't play well.  I don't -- I hardly play at all.  I'm all out of prac----") (100).  Here and at the end of the novel are the only two places we catch glimpses of the type of person Klipspringer is.