Tattletell resembles an elderly woman, which is shorter than most Yo-Kai in the series, easily fitting in Nate's hand. She has long arms, easily wider in length than her body and diminute 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 people reveal their secrets without realizing.
She is shown mostly talking using "Baban" (Japanese: ばばーん,Babān, "telltell" in the English dub) for everything, but does show she can speak normally.
Her most notable ability revolves around causing people reveal their deepest secrets without them realizing. She triggers the possession by clinging on to the victim's face. This ability is also shown to work in 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.
Tattletell makes her debut in EP002, when she possesses Katie and has her reveal Nathan's trip to the restroom. Frustrated, Nathan confronts the Yo-Kai and summons Jibanyan, only to him falling victim to Tattletell's ability and leave the scene embarrassed. After trying to summon Happierre to no avail, as the Yo-Kai refused the summoning due to being on holiday with the missus (in the original, they went to Hawaii), Nathan decides to summon Walkappa as a last-ditch attempt to end the situation. When Tattletell attempts her ability on the Kappa, the latter's revealed secret is amusingly not embarrassing, which causes the elderly Yo-Kai to lose stamina; after trying several more attempts to Walkappa until it was dusk, with the same results, Tattletell falls exhausted, and Nathan manages to convince her to give him her Yo-Kai Medal. 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 EP004, 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 EP011, Tattletell is summoned to try to chat with Noway, but she failed after Noway inspirited her instead.
In EP027, Tattletell was in Yo-kai-lifornia where she was among the Yo-kai waiting in line for the release of the Yo-kai Watch Model Zero.
In EP059, 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 EP064, 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 M01 during the final battle against Dame Dedtime along with others Yo-Kai by Nate. In the first part of battle she is seen being chased by a Wicked along with Pittapat. When Kin & Gin and Duo have been defeated Nate order to Tattletell to enchance Dame Dedtime in order to discover why she is acting so badly. Under Tattletell's possession Dame Dedtime reveals that in her early Life she was a human who was imprisoned unfairly and died in jail and after this she begin to get furious causing Tattletell to escape from her.
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.