Manda

is the king of snakes and is summoned by Orochimaru. He demands 100 human sacrifices after he is summoned. He first appears in Episode 96, summoned jointly by Orochimaru and Kabuto (as Orochimaru had his arms rendered useless by the Third Hokage in episode 79).

Personality
He is very snobbish and prideful, believing himself superior to everyone, and while he does what Orochimaru asks, it seems to be only because he wants to. When Kabuto attempts to calm him (note that Kabuto calls him 'Lord Manda', again reinforcing the snake's pride) Manda merely tells him to shut up, calling him a 'bug.' Kabuto at this point says something about Manda betraying them if he finds out that Orochimaru's arms are useless, making a comment about his loyalty. Manda obviously will not be in anything if there is nothing in it for himself, showing his greed. He mentions at some point that he doesn't like being summoned, leaving the impression that Orochimaru doesn't do that often. He doesn't seem to respect Orochimaru at all, even going to the extent of threatening to eat the Sannin when he is angry. When exchanging insults with Gamabunta he once again shows off his pride, as well as his confidence. He's very strong and he knows it, threatening to 'pop' Gamabunta (Gamabunta then repels this by saying that he wants a snake skin wallet).

Search For Tsunade Arc
After Tsunade heals herself from what should have been a fatal attack, all three Sannin decide to use their most strongest summons and all three succeed at the same time, thus summoning Manda. At first he nags about the fact that he had been summoned and talks down to Kabuto, who tried to answer for Orochimaru.

However when he is taunted by Gamabunta, he is quick to start the fight, only to be tricked by Katsuyu whom he tried to squeeze to death, and is almost burned to death by Gamabunta, if not replacing himself with his shedded skin. After a short battle, where none of the three animals seems to be getting nowhere he however tricks Gamabunta and was about to kill him when he was finally disabled and put out of the fight when Tsunade shoved Gamabunta's dagger through his mouth, pinning him to the ground. Manda stated that because of this, he won't be able to eat for a week and tells Orochimaru that he better be ready to pay the price for this.

Hunt for Uchiha Arc
After Sasuke defeated Orochimaru in the Part II, he used his Sharingan to control Manda when summoned during a fight with Deidara. Manda was killed by Deidara's suicide explosion when Sasuke used him as a shield with Manda cursing Sasuke for this. Suigetsu nagged Sasuke for doing that.

Abillities
Manda is very powerful, and able to stand his own against Gamabunta and Katsuyu and had almost killed them both before being disabled (though this is to be expected as Frogs and Slugs are a snakes prey). He is extremely fast, as he is quickly able to dodge and disable Katsuyu, and incredibly intelligent. 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 somewhat like a Replacement jutsu, which is seen during the battle with Gamabunta and Katsuyu, and to move underground.

Trivia

 * According to Suigetsu, Manda was Orochimaru's first pet.