Just So stories were named by Rudyard Kipling in his book of the same name, which contained stories like “How the Rhinoceros Got his Skin.” In that one, the rhino’s skin starts out tight, but after he takes it off to swim, a man put crumbs in it to take revenge for the rhino eating his cake. When the rhino put his skin back on, it itched so much he loosened it up with all his scratching. Presumably something similar happened with basset hounds.