Tails Doll
From Sonic Retro
Tails Doll (sometimes mistakenly called "Puppet Tails") is a secret character in the game Sonic R, unlocked by finding the 5 tokens in the "Radical City" track and finishing 1st, 2nd, or 3rd in the race. Tails Doll has poor handling, average acceleration and average top speed. Its jumping abilities are quirky; it cannot jump very high, but seems able to float. It is also the only character who can float over the water without slowing down after a period of time.
Tails Doll seems to be one of Dr. Robotnik's creations. Sonic R features metal versions of Sonic and Knuckles. However, in place of a "Metal Tails", there is Tails Doll, an unusual move. Tails Doll was most likely created by Traveller's Tales, the team that worked on Sonic R. This likely explains why he has not yet appeared in another Sonic game. Although similar-looking dolls appear along with Sonic dolls and Knuckles dolls in Sonic Adventure DX: Director's Cut as targets in E-102's first level, these Tails dolls do not have red jewels.
Tails Doll's appearance is as mysterious as the character, and many people wonder about the strange jewel on its forehead that it supposedly draws energy from. This has not yet been verified and probably never will be, for SEGA and Sonic Team have not used Tails Doll in any further productions.
It is assumed that Tails Doll and Metal Knuckles did not, unlike Metal Sonic, gain sentience and therefore would likely have been deactivated by Robotnik or destroyed by Sonic, whereas Metal Sonic appears to have gained a sort of will to live. It is unlikely Tails Doll will appear again in the series.
Tails Doll in Sonic Fandom
Tails Doll has a small following among Sonic fans due to its supposed "creepy" look in comparison to the other robotic counterparts in the game, Metal Sonic and Metal Knuckles. In many fanfiction projects, Tails Doll is supposedly able to materialize and slaughter, possess, enslave, or suck out the souls of those who complete Sonic R or tag Super Sonic as Tails Doll.