Hunter-nin

are a special team within Kirigakure's ANBU, given the specific duty of hunting down missing-nin. They kill their target, taking the head as proof, and then completely dispose of the body by using various methods, such as cremation or the summoning of wild carrion crows to devour the corpse. This is done in order to make sure the village secrets which a ninja's body holds -- such as chakra types, herbs eaten, ninjutsu, special medicine, and kekkei genkai -- will not be revealed to outsiders. Hunter-nin are also supposed to destroy the corpse at the very spot the body is lying; it is not to be moved after it is dead, and only the head is taken back to prove that the missing-nin is in fact dead. As a requirement, they must possess a thorough and intimate knowledge of human anatomy. Due to their reputation for utterly and completely obliterating the remains of their targets, they are code-named "The Undertaker Squad." Early in the series, Haku poses as a hunter-nin as a ruse to rescue the supposedly killed Zabuza Momochi. Real hunter-nin have only been alluded to, and so far have not been seen in the world of Naruto.