The tails doll is a mysterious creation made by Dr. Robotnik. The Tails doll made it's first appearance when it raced for Dr. Robotnik in the World Grand Prix. The tails doll is obviously tails' counterpart, unlike the MK series the tails doll has no visible weapons or personality and no information was obtained from tails to create the tails doll as he did not go through the bio data scanning technique that was used on sonic and knuckles for the MK series. The tails doll appears just to be a stuffed doll who just remains suspended in mid-air. His technology however is unique because he is not kept afloat by any visible rocket boosters or jet packs... maybe the Doc is experimenting with some more advanced technology.