The star of Blue's Clues, Blue, is a female puppy who communicates to her owners (Steve, Joe, and Josh) through barks, which they can partially understand based on her expression and tone. Every episode, she initiates a game of Blue's Clues, in which she leaves three pawprints for the host and the viewer to find in order to find the answer to a question.
Like most puppies, Blue is energetic and playful, but she is also very smart and friendly. She can get angry or sad at times. According to "Blue's First Holiday" and the next episode "The Legend of the Blue Puppy", Blue is very different from other puppies, and not just because of her color. While other puppies like to dig up bones, this puppy likes to read, draw pictures, or listen to music. Blue is described to be the smartest of all puppies.
Blue is a sky blue puppy with darker blue spots and a dark blue nose. Her eyes are white with black pupils. Her tongue is pink if she licks something. She has big, floppy ears.
Blue appears in every episode of both Blue's Clues and Blue's Room, totaling to 160 episodes overall. Her first appearance in an aired episode was in "Snack Time", though she also appeared in the unaired pilot, "Blue Prints". Her last appearance in an episode of Blue's Clues was in "Bluestock", and her final appearance in a Blue's Room episode was in "Music Stars".