According to Urban Dictionary, the obnoxious modern interjection "woot" derives from the world of role-playing games. Long before that, however, it was the name of an Ozian wanderer. His only canonical role is in The Tin Woodman of Oz, and Jack Snow (I believe it was him, anyway) once proposed that the name could have come from rearranging the initials of the book's title (leaving out "the," of course). I'm sure we'll never know if this is true.
Woot is a Gillikin boy, whose original home was near Oogaboo, in the far northwest of Oz. His hometown was happy and content, so seeking more excitement, he decided to wander throughout Oz. In the course of his wanderings, he came upon the Tin Castle, and accompanied the Tin Woodman and Scarecrow on a journey to find Nick Chopper's old lover, Nimmie Amee. He spends a significant portion of this journey in the form of a green monkey, until Ozma transferred that form to its perpetrator, the giantess Mrs. Yoop.
Woot is a quite polite boy, usually providing the voice for NOT barging in on any strange community or dwelling the party comes across. As he remains wandering at the end of the tale, he certainly has potential to appear in more stories, but creating conflict would probably require teaming him up with other characters.