Theo Raeken

Theo Raeken is a supporting character on Teen Wolf and its fan-sequel Cage Unleashed who made his first appearance in the former in Season 5. He was the first Chimera created by the Dread Doctors who managed to successfully complete his transformation without rejection, though he was not considered a true success. He is currently in a relationship with Luke Caelus.

Background
He went to school with Scott McCall and Stiles Stilinski, in the fourth grade, before his family left Beacon Hills following the "mysterious" death of Theo's sister.

Teen Wolf
Theo returned to Beacon Hills and claimed that he wanted to join the Scott's pack pretending to be a recently-bitten Beta whose Alpha had died before his first full moon, when, in reality, he wanted Scott's pack for himself, choosing to get close to them to manipulate them into turning against Scott. When his plan failed, Theo killed Scott himself and moved onto his Plan B, which involved resurrecting four of the "failed" Chimeras before informing them that they were now his pack, and he was their Alpha (despite the fact that he was neither an actual Alpha nor a real Werewolf).

He continued his quest for more power with the help of his pack, only this time, he focused his sights on stealing the powers and lycanthropy of the Beast of Gevaudan, who had recently been resurrected by the Dread Doctors. To do this, he pursued several different leads that he thought could help him achieve his goal, including obtaining Belasko's talons, capturing Deucalion, and attempting to capture Lydia Martin, knowing that her Banshee connection with Jordan Parrish, the Hellhound prophesied to battle the Beast, would lure both Parrish and the Beast to him. He even killed two of his "Betas," Tracy Stewart and Josh Diaz, in order to steal their powers of Kanima venom production and electromagnetokinesis, respectively.

However, Theo's plans once again failed when the Beast proved immune to his venom. When he tried to retaliate against the McCall Pack for thwarting his plans with Deucalion's help, Kira Yukimura, with the help of the Skinwalkers, summoned Theo's deceased sister to drag Theo through a sinkhole and trap him underground. Theo's remained imprisoned beneath the underground tunnels of Beacon Hills until he was set free by Liam and Hayden in Ghosted.

Theo helped with McCall and his pack in dealing with the supernatural forces in the series finale. Although he was able to make good terms with Scott in end, he was nevertheless secretly bitter with Scott over his failed plans and secretly plans to start a new pack without any interference from him.

Cage Unleashed
Several weeks after the events of Teen Wolf, due to his action against his alleged "parents," Theo is now homeless and is forced to live in his truck, struggling to find a place to sleep without being forced to move by cops due to loitering policies.

Fortunately, his homeless problems came to an end after meeting and becoming friends with an upper-class, freshman college student named Lucas "Luke" Caelus. The latter was completely oblivious to Theo's past, let alone him being a Chimera, and Theo was able to take advantage of Luke's cluelessness by convincing him to let him stay at his apartment.