Courage finds a bone in the backyard, which turns out to be the bone of the extinct kangaroo monster as Courage’s compter says.(Apparently the scientists weren’t very creative in the name). A whole skeleton is found and Eustace sells bones to scientists. When Courage comes Eustace accidently falls off the roof, and their doctor says a bone transplant is needed. Courage decides to use the kangaroo monster bone to transplant into