Here's the breakdown:
* Origin: The Tails Doll is not an actual character in the Sonic games. It's a glitch or a corrupted texture found in the Sega Saturn version of *Sonic R*. The glitch makes Tails appear with a twisted, grotesque face and red eyes, giving it a sinister appearance.
* Creepypasta: The Tails Doll gained notoriety as a creepypasta, a horror story spread online. The stories claim that the Tails Doll is cursed, possessed by a malevolent spirit, and can haunt players of *Sonic R*. Some accounts allege that the doll can even cause physical harm to players.
* Popularity: Despite being a fictional creation, the Tails Doll has become a popular meme and symbol of creepypastas. It's often featured in horror videos, artwork, and even fan-made games.
The Tails Doll is a prime example of how glitches and online folklore can blend together to create a terrifying and enduring urban legend.