Tonton

is Tsunade's pet pig, often kept in the care of Shizune.

Personality
Above all else, Tonton is a highly devoted, and dutiful pet pig. Her devotion to Tsunade was noted during her master's battle with the other Sannin, which she watched in earnest as Gamakichi, and Gamatatsu bickered. This even surfaced during the Fourth Shinobi World War, where, in her earnest to aid the Logistical Support and Medical Division, Tonton carried around several large sized crates around the camp ground, eventually spraining her foot.

Tonton does not speak in any human language, but still manages to get her point across by whining in her own unique tone (a "buhi" or "oink" depending on the language). It seems that Tsunade and Shizune are able to understand what Tonton is trying to say. Tonton's nose also seems adept at tracking things, so much so that Pakkun has some familiarity with her.

Appearance
Tonton is of a light pinkish colour, much like any other pig. Her cheeks blush in a darker shade of the same pink as her skin. She is always seen wearing a pearl collar and a dark red jacket.

Abilities
Tontons sense of smell is noted to be even finer than that of a ninken. She has reportedly smelled debt collectors coming and saved Tsunade from them countless times while they were not in Konoha. She was also able to direct Shizune, Jiraiya, and Naruto to Tsunade's location after she was locked in battle. Also, despite her small size, she is strong enough to carry several crates at least as large as her.

In the video games, Tonton often acts as Shizune's partner in some of her techniques. In the anime, Tonton performed a Transformation Technique, appearing as Tsunade (although she did not speak). It could be that Shizune performed the technique on her, just like she does in the video games.

Search for Tsunade Arc
While travelling with Shizune and Tsunade, Tonton encountered Orochimaru and Kabuto, who were hoping for Tsunade to cure Orochimaru's arms. She is later seen on the battlefield watching the battle along with Gamakichi and Gamatatsu.

Mizuki Strikes Back Arc
Tonton was later seen during the escape of the criminals from the Konoha Strict Correctional Facility. She used her keen sense of smell to find the escapees until she was relieved of these duties by Pakkun.

Invasion of Pain Arc
Tonton was present when Naruto was informed of his master's death, with Shizune holding her in her arms.

Chikara Arc
Tonton was present when Tsunade tasked Team Kakashi with the mission to investigate the massacre of the Tonika Village.

Confining the Jinchūriki Arc
When Tsunade awakes from her coma, Tonton looks pleased to see her up until Shizune mistakenly believes that Tsunade wanted to eat Tonton to regain her stamina, much to their panic.

Shinobi World War Arc
Tonton was later assigned to the Logistical Support and Medical Division alongside Shizune. When Shizune introduced her to the division members she expressly told them that Tonton wasn't food. During the night when the Alliance's forces had retreated for protection and treatment, Tonton busily carried crates around the compound despite Shizune's behest to not overdo it.

Tonton had to later be tended to by Shizune as she had sprained her right front leg after carrying too many heavy crates.

Naruto 6: Road to Ninja
Tonton is completely black in the Genjutsu World, and also far more aggressive, seeming almost scary.

Trivia

 * In the video games Naruto: Ultimate Ninja 2, Naruto: Ultimate Ninja Heroes 2: Phantom Fortress, Naruto: Ultimate Ninja 3, Naruto Shippūden: Ultimate Ninja 4 and Naruto Shippūden: Ultimate Ninja 5, Tonton is used by Shizune in "Hog Release: Tonton", which is a technique that throws Tonton at an opponent while spinning upward. In Naruto Shippūden: Ultimate Ninja 4, Tonton is used as a partner to Shizune, helping her out in her Ultimate Technique by transforming into an image of Shizune and attacking the enemy to distract them from Shizune's main attack. In Shizune's Chakra Sword: Great Intersecting Wound, Tonton butts the opponent in the stomach to knock the enemy back for Shizune's main attack.
 * In Naruto: Path of the Ninja 2, Tonton could be summoned to break rocks in the player's path.
 * Tonton shares the same voice actress in both English and Japanese versions of the anime as Shizune.