After merely hearing of "the Beast", Valkyrie assumes that it is a terrifying monster, something to which Myosotis Terra agrees as she rescues her. They discover that it is actually a cute creature that the cannibals didn't have the heart to kill and eat, instead naming it "The Beast" because it was funny. Myosotis and Valkyrie decide to rename it "Fluffy".
It is 2 feet tall with small arms and tiny hands. It is covered with fur except for its face, which harbours two large eyes, a small snout and little ears that twitch.
The name "Fluffy" may be a reference to the three-headed dog of the same name in the Harry Potter series. Derek has mentioned before that he is a fan of the books and the fact that The Beast is an innocent creature with a terrifying name is a reversal of Fluffy being a terrifying creature with an innocent name. This has not been confirmed by Derek.