Eight Branches Technique

This is Orochimaru's greatest and strongest snake-related technique. Using the "power of reincarnation" possessed by the White Snake as an intermediary, he can transform into a giant white serpent with eight heads and eight tails. The serpent boasts a giant body, even larger than that of Manda, who was feared as the "strongest colossal serpent". Just by crawling on the scales of its abdomen it was able to trample the Uchiha hideout, and could destroy most things without difficulty. This technique transcends the "Snake", and becomes like a "Dragon God".

When using this technique, Orochimaru can emerge from the mouth of one of the heads and use his Sword of Kusanagi to attack, even without a host.

Trivia

 * The name of this technique comes from the legendary snake Yamata no Orochi, a monstrous eight-headed and eight-tailed snake that was destroyed by the god Susanoo-no-Mikoto. This is a reference to how Itachi's Susanoo killed the serpents produced by this technique.
 * In Naruto Shippūden: Ultimate Ninja Storm 2, the eight snakes' heads can unite to create a devastating energy attack similar to a Tailed Beast Ball from a tailed beast that was powerful enough to overwhelm the defences of Itachi's armoured Susanoo, even with it using it's Yata Mirror for defence.
 * Despite the fact that this technique was stated to be the product of Orochimaru's years of human experimentation and the Living Corpse Reincarnation technique in the manga, in the anime, it was stated that Orochimaru, upon defecting from Konohagakure, stole the scroll from the Hokage Residence with the information on this kinjutsu.