Sweet Polly Purebred is a female anthropomorphic dog TV news reporter who is Underdog's love interest, and she often serves as the damsel-in-distress of most episodes. When being pursued by an antagonist, Polly is apt to start singing, "Oh where oh where has my Underdog gone," in a whiny voice, hoping for the object of her affections to come and rescue her. Polly's face is slightly similar to that of Underdog's with a large muzzle and nose, and she has platinum blonde hair styled in a pageboy, and her wardrobe consists of a black skirt, a white shirt, a red sweater, and black high-heels. In a few episodes it is hinted that Polly shows her love for Underdog. In the episode "March of the Monsters" she is caught by a robot and calls for Underdog. He then saves Polly but after Underdog uses his sci-fi noise and breaks all the glass the towns people complain about his noise. However Polly defends the hero and tells the people that they should thank him for saving everyone from the robots. She then goes to reward Underdog with a big kiss but the hero backs away and flies away. Also in the episode "The Vacuum Gun" she is caught by Simon Barsinister's vacuum gun so then she calls for Underdog which her song annoys Simon. Later in the episode she retrieves Underdog's ring.In the live-action film, Polly is a Cavalier King Charles Spaniel owned by a girl named Molly. She is based upon Superman's romantic interest Lois Lane.She was voiced by Norma MacMillan in the cartoon and voiced by Amy Adams in the live-action film.