Eight-Headed Flame Dragon

The Eight-Headed Flame Dragon (八頭部の火竜 Hachibu no Hiryū) is a eight headed dragon spirit composed entirely of flames. While it's power is similar to a bijū and it's eight heads gives the impression that it is one, the Flame Dragon is more similar to the Zero-Tailed Masked Leech than an actual bijū.

The Eight-Headed Flame Dragon came into existence around a similar time as the bijū, however, it was merely the deceased spirit of a dragon at the time. It went in search of a vessel and found the body of an Uchiha, attracted by the shinobi's affinity for flame based jutsu. Since then, the Dragon has made a pattern of choosing only Shinobi whose chakra affinity if the Flame as it's host. As the first host died, it became the Dragon's second head of his own will. Now, the two headed creature set out in search of a new host over the many years it lived, and, whole having more than six more hosts, only six of the hosts it had chose to become another head. Due to the multitude of heads residing on the Dragon's "body", it has multiple personalities, one for each of the heads. Each can make their own decisions, but only one head in the current leader.

The Eight-Headed Flame Dragon, is fully capable of sealing and unsealing itself into a host of it's own choosing, unlike bijū, who are forced to be sealed inside a host, called Jinchūriki, by a shinobi. Also, the Eight-Headed Flame Dragon unsealing itself from it's host does not result in their death. However, the Dragon rarely chooses to unseal itself until the hosts death, as, normally, the host and Dragon have a very relaxed relationship, being able to converse in a mindscape similar to that of a Jinchūriki of their own will.

Abilities
As it's name implies, the Eight-Headed Flame Dragon's primary ability is pryokinesis or flame summoning and manipulation.