La Bête du Gévaudan

Sebastian, more commonly known as La Bête du Gévaudan, or The Beast is one the two main antagonists in the second half of the MTV series Teen Wolf. La Bête du Gévaudan is a French legendary ancient werewolf and is described as “History’s most vicious, most famous werewolf.”

Season 1
The beast is first mentioned in Season 1, when Allison Argent learns that one of her ancestors killed the beast after his wife and four children were first to fall prey to the creature back in south-central France during the 1760's.

Season 5
Centuries later, the beast is resurected by the The Dread Doctors in order to have it kill for them and to believed they wish to steal its power. The beast constantly hunts down most of the people in the town during this time as Liam and Hayden are chased by the Beast and, later, Scott and Stiles investigate the remains of its previous attack. The Beast menaces Theo and Tracy when two of the Dread Doctors tell Theo to stay out of their way. Hunter Chris Argent later goes to his father Gerard Agent, getting his help on what he knows about the monster and how to defeat it.

It later shows up while Malia and Breaden rescue Dr. Deaton and while Malia is fighting the desert wolf.