Twilight had two similar creatures: the shapeshifters and the Children of the Moon, and only one of them is considered actual werewolves.
The Twilight Saga introduced a different type of werewolves, but as it turns out, there are actually two types of these creatures in this universe, and only one is considered the true werewolves. In 2005, Stephenie Meyer shared her unique vision of a world where vampires, werewolves, and humans coexist in her debut novel Twilight, the first entry in a series of four novels. The core of the series is the romantic relationship between human Bella Swan and vampire Edward Cullen, who had to overcome a number of obstacles so they could finally be together forever – literally forever.
The Twilight novels were a huge success and made way for a worldwide phenomenon, so it wasn’t surprising when the books were adapted into movies. The Twilight Saga was released between 2008 and 2012 (with the final novel, Breaking Dawn, split into two movies) and was very well-received by fans of the novels, but not so much by critics and the rest of the audience. Still, the movies brought this universe closer to the audience and expanded the books’ fanbase, but it also made way for a lot of questions about this peculiar world and its creatures, especially when it comes to the werewolves, who just like the vampires, are very different from the classic monsters that have become part of pop culture.
Werewolves are introduced in the Twilight universe through Bella’s best friend Jacob Black (Taylor Lautner), and unsurprisingly, these creatures and vampires turned out to be enemies, though they had a deal so they wouldn’t fight and thus their true nature wouldn’t be revealed to humans. However, Jacob and the rest of the pack weren’t actually werewolves but shapeshifters, even though they did turn into (big) wolves. The differences with the mythical werewolves are that shapeshifters don’t need the full moon to transform and their condition is the result of a gene, though not all those direct descendants of the Taha Aki end up phasing, as it’s something that has to be triggered .
On the other hand, there are the Children of the Moon, who are the real werewolves of the Twilight universe. Children of the Moon are more like the werewolves everyone knows, as they do need the full moon to transform into feral wolf-like creatures (not actual wolves, like the shapeshifters), and they can’t control their transformation. Unlike shapeshifters, they are strong enough to kill a vampire, which led the Volturi to almost eradicating all werewolves from Europe and Asia. When a Child of the Moon transforms, they lose their human consciousness and become fully feral, and their “condition” is spread by infecting other humans through a bite, and infected humans can’t pass it to their offspring. However, unlike traditional werewolves, they can’t be killed with silver bullets nor can you repel them with them, and it’s unknown how they can be defeated.
Unfortunately, not much is known about the backstory of werewolves in the Twilight universe as they are not often creatures seen in the novels, and they were completely cut off from the movies. Unless Stephenie Meyer decides to explain these creatures at some point, they will remain as some of the most mysterious presences in the Twilight universe, and it’s up to the imagination of fans to decide how dangerous they are and how their presence will affect the rest of the characters.