The Tails Doll has several weaknesses that can be utilized to subdue or possibly even defeat the Tails Doll. Tails Doll can be injured by conventional means, such as with knives or guns, but these are difficult to attack it with. It is best to keep in mind that while these may keep the Tails Doll at bay and weaken it for a little while, they can't completely stop it.
List of Weaknesses
Live and Learn
The song Live and Learn by Crush 40 is possibly the most effective weakness the Tails Doll has. Playing the song causes the Tails Doll to weaken and go deaf.
The Tails Doll is weak to plushes of Sonic, which can be used with similar effect to holy water or garlic has to a vampire, burning the Tails Doll and otherwise injuring it.
In some stories, people have chanted the Japanese name for Sonic the Hedgehog, Sonikku za Hejjihoggu in order to freeze the Tails Doll in its tracks.
Shadow the Hedgehog
The Tails Doll has a sort of fear of Shadow the Hedgehog. Images of Shadow may be used to ward it off, but the power is weak and otherwise has little effect on it. The video game Shadow the Hedgehog has particular power over it, however, and can be used to stop the Tails Doll. It is possible that the Tails Doll Curse could not be performed using a memory card with data from Shadow the Hedgehog on it, but this is unconfirmed.
Seven Pure Souls
The Seven Pure Souls are people with pure souls. With their efforts combined, they are the only one who can truly kill the Tails Doll. This is the only life-threatening weakness the Tails Doll actually has.
Eighth Pure Soul
The Eighth Pure Soul can be considered the antithesis of the Tails Doll, the direct polar opposite, and therefore has the power to stop the Tails Doll. The Eighth Pure Soul is a mysterious being and has never been seen or heard of, if him or her even exists in the first place.