Tart arrives on Earth with Pie to assist Kish in preparing for Deep Blue's arrival. Energetic and frequently childish, Tart mocks Kish for his losses against the Mew Mews, calling him weak. Like Pie and Kish, Tart has the abilities to fly, teleport, and create chimera animas. His primary combat style involves physical attacks and using chimera animals, but he can also manipulate plants to bind people and execute an energy beam attack. In the anime, he is seen fighting with a click-clack toy as well.
Tart doesn't get along with Ichigo and often bickers with her until they resort to name-calling. He can't comprehend why Kish would have feelings for someone he considers an "old woman." Tart particularly despises being called a "midget," which Ichigo exploits to trick him into freeing a captive Pudding by taunting him into reckless attacks. Alongside Pie, he once captured Pudding, with Tart overseeing her under the Tokyo Dome. During this encounter, Pudding confounds him by refusing to cry, speaking kindly to him, offering him candy, and calling him her "buddy."
After being defeated by the Mew Mews, Tart labels Pudding as "spooky" but then chuckles upon looking at the candy she gave him. In the anime, instead of being rescued from an underground cavern by the Mew Mews, Pudding is saved by Tart when he notices she is struggling to breathe due to a lack of oxygen. Towards the end of the anime, Tart catches Pudding when she collapses from exhaustion and expresses his desire to stop fighting. Pudding tells him that being with her makes him stronger, bringing her face close to his.
At the conclusion of the manga series, after Pie and Tart are defeated by the Mew Mews in the final battle, Tart confesses to Pudding that he never hated her, causing her to weep. After Deep Blue's defeat and the aliens' preparations to return to their world, Pudding becomes emotional about Tart leaving and kisses him while giving him a candy drop. She also presents him with additional gifts, expressing her wish that it wasn't goodbye. Tart blushes and suggests he might come back for another candy drop.
In the anime series, Tart's voice actor is Asai Kiyomi. In the English adaptation of Mew Mew Power, his name is changed to Tarb.
