Tattletell resembles an elderly woman, which is shorter than most Yo-Kai in the series, easily fitting in the palm of a human hand. She has long arms, easily wider in length than her body and diminutive legs. She also has an oval-shaped head and her inner mouth and tongue are green-colored with a single bucktooth in the maxilla.
Her eyes are round and her hair is white and kept in a bun, enhancing her elderly appearance. She dresses in a white shirt, a dark purple shawl and a dark red skirt.
She is very mischievous and enjoys making others reveal their secrets without people realizing them, and shown mostly saying "Tell! Tell!" ("Babaan" in the original adaptation) for everything, but does show she can speak normally.
She triggers the possession by clinging on to the victim's face, whether it is a human or Yo-kai. The only drawback of this ability is if the victim's secrets are not embarrassing, such as Walkappa's. Tattletell will not feel satisfied; if the possession attempts are constant and with the same result, her stamina will decrease gradually.
She seems to know Hungramps, he later recognized her and even invited Tattletell to drink some tea together during his confrontation by Nate.
Yo-kai Watch animated series
Tattletell makes her debut in Why Did You Say That?, when she possesses Katie and has her reveal Nathan's venture to the public toilets. Fustrated, Nathan confronts the Yo-kai and summons Jibanyan, only to him falling victim to Tattletell's ability. After trying to summon Happierre, the Yo-kai refused to be summoned as he was on vacation with Dismarelda. Nathan decides to summon Walkappa as a last-ditch attempt to end the situation.
When Tattletell attempts her ability on the summoned Yo-kai, the latter's revealed secret is amusingly not embarrassing, which causes the elderly Yo-kai to lose stamina. After trying several more attempts to reveal a terrible secret from Walkappa, Tattletell falls exhausted and Nathan manages to convince her to give a Yo-kai Medal to Nate.
Later in the same episode, Nathan uses Tattletell to discover the cause of Katie's upsetting and asks the Yo-Kai to discretely help Katie with her mother.
In Yo-kai Hungramps, Tattletell is summoned to inspirit/possess Hungramps to find out why he's haunting a convenience store, temporarily stopping only for some tea when Hungramps stopped her for it.
In Yo-kai Noway, Tattletell is summoned to try to chat with Noway, but she failed after Noway inspirited her instead.
In Yo-kai Suspicioni, she inspirits Nate's friends because Nate was suspicious they were not really friends. However, Bear, Eddie, and even Katie admit they like him and that they are friends, thus foiling Suspicioni.
In Yo-kai Dummkap, she forces Dummkap to reveal his origins to herself, Nate, and Whisper. His story attracts Wazzat and the two hat Yo-kai become friends.
Yo-kai Watch: The Movie
Tattletell is summoned in Yo-kai Watch: The Movie, during the fight against Dame Dedtime along with other Yo-kai summoned by Nate. In the first part of battle, she is seen being chased by a Wicked along with Pittapat. When Kin & Gin was defeated, Nate orders Tattletell to try and reveal Dedtime's secret on why she was acting so badly.
After Dedtime explains about her origin, she begins to get furious, causing Tattletell to escape from her. Though, it is unknown if she used her Soultimate move when she was fighting Dame Demona.
In EP084, she makes a brief cameo in "Jibanyan's summer break" when Jibanyan asked her if she knows where the cat's owner was, but for the first time, she didn't know who that owner was.
In EP121, it is revealed she can speak normally and possesses herself in front of Hungramps, USApyon, and Inaho to reveal how she became a Yo-kai.