The Dog is a dog of unknown gender. It appeared during the end credits. We never hear the dog's name.
The dog is medium-sized, with pointy ears, and black fur with white on its muzzle, chest, tummy, paws and the tip of its tail. Its eyes are large and brown. It has a shortish, pointy tail. It seems to walk with a lolloping waddle and move its head kind of like a bird.
Its mind looks similar to Riley Andersen's mind, with the emotions working in tandem. The memories seem, like Riley's, to be mostly happy, with an occasional memory of another color. The dogs' emotions simply look like the dog, but with the black fur being replaced with the color of the emotion. For example the dog's Joy has yellow fur, its Sadness has blue, etc. They communicate in barks. The emotion Joy doesn't wear any clothes, and neither does the dog itself, but like Riley's emotions Fear wears a purple bow, Anger wears a red and white tie, Sadness wears large blue glasses, and Disgust wears a magenta bandanna.
(in dog, subtitled as) "I smell food"-Joy