Tails Cookie (Korean: 테일즈 쿠키, teiljeu kuki), or simply Tails, is a Special Cookie released with Head sonic.png Sonic Cookie and Head moon rabbit.png Moon Rabbit Cookie in the second part of the Heart of Courage and Passion update (version 2.0.102). He is of the Ambushclass.webp Ambush type and his position is prioritized to the Middle. Tails Cookie was added to the game as part of a special Devsisters x SEGA collaboration for Sonic the Hedgehog's 30th anniversary. He does not appear in the standard Cookie Gacha and could only be obtained via the crossover event. As the event has ended, he can no longer be obtained in-game.

Tails is a very special fox. Why? Because he can fly thanks to his two tails! Tails wasn't always happy about being different, but with Sonic's help, he has gained the courage to accept himself. Of course, now the two are the best friends in the world! Tails knows his way around tools, mechanisms, and robots—that's for sure. This little genius is always working hard, tinkering on new inventions to help save the world!

Holding this stone in your hands, you feel like you understand machines and mechanisms a bit better. It also makes you want to care for your friends.

Tails Cookie and Sonic Cookie are the first Special Cookies to be added to Cookie Run: Kingdom. Alongside Sonic Cookie, Tails Cookie is one of the first Cookies to be released with a full English voiceover. Tails Cookie has no Korean audio and instead uses his English voice lines if the game is set to Korean audio. All of his lines appear to be recycled from previous Sonic the Hedgehog games and media. Tails Cookie's English voice actress, Colleen O'Shaughnessey, also voices 페스츄리. Tails Cookie's internal name is "cookie0526".