Duke and Annie are puppies in Scrappy-Doo's old gang from his old neighborhood in New York City.
Duke is a small tan terrier with black spots on his back. He wears a red collar with a red triangle-shaped dog tag. He mostly live in a box in an ally next to Annie's house and doesn't like it when Scrappy rushes in things. Duke is an expert at getting to places around New York.
Annie is an old English sheepdog with hair covering her eyes. She wears a black necklace with a pink heart-shaped dog tag. She lives in an old apartment building and hardly sees anything (due to the hair in her eyes).
They are both the only ones who seem to enjoy Scrappy's Secret Whistle (Scrappy whistles in a high-pitched sound which is so loud.