Tails Doll

The Tails Doll (Te-Ru Doru) (mistakenly called Puppet Tails or Tails Puppet) is a robot / doll version of Tails built by Dr. Robotnik. He is comparable to Tails in the same way that Metal Sonic is comparable to Sonic. Tails Doll has a metal rod coming protruding out of the top of its head leading to a red gem that seems to control the creature's movements. Tails Doll is able to float on water, making him very useful in tracks with large water areas, which makes up for his slow speed. Tails Doll appeared only in Sonic R, as an unlockable character on the Radical City course by collecting 5 Sonic Tokens.

Trivia
Although not the same character, in Sonic Adventure, there are doll versions of Tails, Sonic, and Knuckles used as practice dummies for Eggman's robots (such as E-102 Gamma in his tutorial level). They appear incapable of moving on their own as the Tails Doll can. In Sonic Rivals, the doll versions of Tails from Sonic Adventure appears on a collectible card and is named "Tails Doll."

In many fan-fictions and Youtube videos, the Tails Doll is believed to be a demon that kills people and steals their souls. This is against anything mentioned on Sonic R and any other games.