Spitfire is a morbidly obese pegasus who is the captain of the Wonderbolts, a squad of pegasi that perform flight shows and feats of acrobatics. She had gained several hundreds of pounds in weight due to junk food sponsorships and her tendency to do "cheat days" when eating. However, she completely denies her huge weight gain and thinks her blubber is all muscle. Spitfire is arrogant and strict like a drill sergeant but good-natured as the captain of the Wonderbolts.