Stranded in America after a crash-landing in an experimental ship with Roger Bacon in Roswell, New Mexico, Hilda decides to travel with the party to sightsee while Roger fixes the ship. A vampire, like her older brothers Keith and Joachim, Hilda fancies herself to be a true super-heroine. Hilda can change forms; while she has a Bat form like the other Valentines, her main ability to change revolves around Calories; positive calories turn her from Slim form to Pink Bat form to Curvy form, while negative calories have the opposite effect. She uses Wands to attack, as well as an elemental set of Magic Arts. It is notable that Slim Hilda is the more magical based version, while Curvy Hilda is physical based. Pink Bat form actually has the strongest attacks, but is very vulnerable. Hilda's primary Element is Earth.