Vampire tattoo

The hunter tattoo has multiple purposes. The tattoo is of the Hunter symbol, which bears similarity to the Cross Academy logo. It can be used to slow the awakening of a human into a vampire, as Kaien Cross advised Zero Kiryu. Zero was able to delay his awakening for four years with its assistance, although he believed it would prevent it.

The primary purpose of such a tattoo is for the taming ceremony. The tattoo is linked via a matching piece of jewellery with a crest of the same symbol on it.

The tattoo can be on various parts of the body, most likely to be at the point where the human was bitten, as this is where Zero has his.The tattoo hurt him because of the vampire who bit Zero.