She may not breathe fire, but the dragon in Gainesville High School’s theater production of “Shrek: the Musical” does just about everything else. Her wings flap, her tongue moves and her head rises up, reaching 7 feet in height, thanks to 17-year-old art student Grace Williams, who built the dragon with the help of her father, Bill. Gainesville’s drama director Pam Ware approached Williams last summer about building a dragon for the production.