Children of the Moon

Children of the Moon, more commonly known as Werewolves, are a species from the Twilight Saga. These creatures are immortal and very strong. Unlike the Quileute shape-shifters, they are generally found in groups of two, rarely in larger groups, and, unlike the Quileute shape-shifters, cannot communicate mentally and therefore far more ineffective. They also lack self-control in their wolf form, during the full moon. The Children of the Moon are not of wolf stock, and are either the descendant of a couple of werewolves or as a consequence of a bite by a werewolf. They are also distinct from the Quileute shape-shifters of La Push, since they turn into wolves at full moon instead of at will. While not appearing in the series, they have been described as the natural enemy of vampires.

History
Not much is known about the Children of the Moon. It is known that Caius, one of the Volturi leaders, is terrified of them after he was nearly killed in a fight two thousand years ago. Aro and Marcus knew about Caius's encounter, and since werewolves pose a threat to vampires everywhere, they initiated a war against them, resulting in the been near extinction of the werewolves in Europe and Asia. It is not known if they are found anywhere else in the world. In Eclipse, it also says that James hunted one across Siberia though unaware it was a werewolf.

The Volturi refuse to tolerate truces or alliances between werewolves and vampires, under likely punishment of death. This was something that Caius tried to stress when the Volturi put the Cullen Family on 'trial' for creating an immortal child. But the werewolves the Cullen's had allied with were really shape-shifters in wolf forms, The law therefore didn't apply.

Appearance and Traits
Due to the Volturi's initial assumption that the La Push shape-shifters were Children of the Moon, the two groups probably look very similar (when transformed). It is also assumed that their abilities are similar but perhaps stronger, although there is little or no evidence to back up either claim.

It is mentioned that Children of the Moon rarely form packs. It is not known if they show a social characteristics similar to the Quileutes', such as hierarchy, however, in Breaking Dawn, it was commented that true werewolves are disorganized compared to the shapeshifters, so it may be assumed that they're solitary and perhaps not even telepathic.

A true werewolf has yellow eyes, which become more prominent during the full moon. Werewolves do not age, show flowing blood and a beating heart like humans, and they probably smell unappetizing to vampires. Werewolves consume flesh, human or animal. Like shape-shifters, werewolves probably have enhanced strength and speed, rapid healing, and heightened senses. It is unknown how strong they are as humans.

It was stated that Caius nearly lost a battle to a werewolf, namely, one werewolf. This means that, like the shape-shifters, the werewolves are just as powerful as the vampires. They may or may not possess gifts. Also, unlike the Quileutes it is possible that they are not fatally poisoned by the vampires venom, which explains why a vampire as strong as Caius almost lost his fight to the werewolves.