Bud is named after the comedian Bud Abbott. His right front paw is pure black. Redish-brown fur covers his entire body, and is decorated by black spots and black rings around his eyes. His purple collar is sometimes shown to release Joker Venom. Bud, like his master, likes to laugh maniacly. His laugh is noticablly higher then his brother, Lou's. Joker never really cared fo the two. Not as much as Harley Quinn. He is now owned by Harley Quinn.
At one point, he was captured (with his bro) because of Mercy Graves, and put in to a zoo. Quinntets sprung both of them out.
Neither has appeared in the "new" 52.
He and his brother deputed in Batman: The animated series, and made various appearances in the show.
They also fought against Ace the Bat-hound and Krypto in Krypto the superdog, in one episode. In it, they used gadgets, and their speech was translated to english.