Buster

Buster is a Basset Hound who was tested with the Youth Formula, curing his ailments and reverting him back to a puppy. Buster also inadvertently brings Buddy Love to life when a loose hair mixes with Buddy's DNA while Buster is scratching himself. Buddy also gains dog-like qualities to his personality as a result which ultimately proves to be Buddy's downfall when Sherman takes advantage of this and tricks Buddy into catching a tennis ball which is laced with a more potent version of the youth formula.