The title character 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 the answer to a question.
Like many puppies, Blue is very 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 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 (very dark blue in the original). Her tongue is pink if she opens her mouth or licks something. She has big, floppy ears.
Blue appears in every episode of all the series in the franchise, including the reboot. Her first appearance in an aired episode was in "Snack Time," though she also appeared in the unaired pilot, "Blue Prints."
In the pilot, Blue was a male cat colored orange (it would later become Orange Kitten), but she became a female dog colored blue because Nickelodeon had already greenlit a show about a cat.
Blue's name would also contradict her color anyway.
When deciding on Blue's voice actor, people went around the room asking each other if anyone can bark. As it turns out, Co-Creator Traci Paige Johnson can do Blue's barks so it was decided that Traci Paige Johnson should do Blue's barks.
Blue can wiggle her toes.
Blue has been one of the three clues in four different episodes.
In episodes 1 and 3, it was herself. In episodes 2 and 4, it was a picture.
Blue was once shy of Miranda (Magenta's owner), but once she took the time to know Miranda, she realized that Blue and Miranda both know Magenta.
Blue appears in almost all of the credit sequences during the show's run, from Season 1-6, except for "Blue's Big Pajama Party" and "100th Episode Celebration," where she is nowhere to be seen, not even at the very end, which she is with her ball at the end of most episodes (her ball didn't appear at the end of Blue's Big Musical).
In the late 1990s and early 2000s, she appeared in many bumpers alongside Face, who was the host of Nick Jr. from 1994 to 2004.
In "Steve Gets the Sniffles," Steve was looking for Blue and he asked the viewers where is Blue then they said on the couch hiding under the blanket then Steve sneaks up and sits next to her then he tickles her so it appears that Blue is ticklish.