Manda

was the personal summon of Orochimaru.

Personality
Manda is very snobbish and prideful, believing himself superior to everyone. He apparently only serves Orochimaru because he could not successfully defeat him, as Kabuto expresses concern that Manda would turn on them if he knew Orochimaru couldn't perform jutsu. Even in this instance, he complains about the conditions he is summoned into and demands that he be given a hundred human sacrifices as compensation for his help. When they lose in this battle, Manda threatens Orochimaru to be prepared for a punishment during their next encounter. Manda and Gamabunta have a mutual animosity for each other.

Search For Tsunade arc
Orochimaru (with Kabuto's assistance) summons Manda to combat Tsunade's Katsuyu and Jiraiya's Gamabunta. After relishing in the possibility of getting to eat the other two summons, Manda attacks. He tries to constrict Katsuyu to death, but she divides herself to escape. Jiraiya and Gamabunta then try to catch him in a firestorm, but he burrows underground to sneak up on them. Before he can land an attack, Tsunade drives Gamabunta's sword through the roof of his mouth, pinning him down and leaving him unable to eat anyone. Angered by the humiliation, he threatens Orochimaru before leaving.

Hunt for Uchiha arc
When Sasuke, at the end of his fight with Deidara, is about to be hit by C0, he summons Manda in order to escape the blast. He uses his Sharingan to place a genjutsu on Manda, allowing him to safely hide in Manda's mouth while Manda takes the brunt of the blast. He tries to summon himself away, but dies of his wounds upon arrival. He curses Sasuke for controlling him with his last breath.

Abilities
Manda is very powerful, and able to stand his own against Gamabunta and Katsuyu and had almost killed them both before being disabled. He is extremely fast, as he is quickly able to dodge and disable Katsuyu. It's also obvious that he's well known, as Gamakichi is afraid of him just because of his gaze. He is also able to shed his skin in a manner similar to the Body Replacement Technique, which is seen during the battle with Gamabunta and Katsuyu, and to move underground.

Trivia

 * According to Suigetsu, Manda was Orochimaru's first pet.
 * Manda's mouth appears to not have a tongue.