|“||You think Stiles-- skinny, defenseless Stiles-- is a Nogitsune? A powerful dark spirit?||”|
|“||Aw, come on! Just give us Derek. You don't want him anyway! Haven't you noticed what a downer he is? No sense of humor, poor conversationalist...||”|
Derek and Stiles first met in the first episode of Season 1, right after Stiles' best friend Scott McCall was bitten by the Alpha and turned into a Werewolf. From the start, their relationship was antagonistic, as Stiles, believing Derek to have killed his sister, found him untrustworthy and suspicious, whereas Derek believed Stiles to be yet another naive teenager like Scott. However, the two began reluctantly working together to protect the humans of Beacon Hills safe from the Alpha, who was later revealed to be Derek's uncle, Peter Hale, as well keeping Derek and Scott safe from the Argent Family of Hunters who were pursuing them.
Though their interactions continued to involve the two being snarky and occasionally even rude, Derek and Stiles began to develop a true friendship, as the members of Derek's pack teamed up with Stiles, Scott, and their friends to protect Beacon Hills from other threats, such as the Kanima, the Darach and the Alpha Pack. During their time working together, each saved the other's life on several occasions. For example, despite Stiles' human nature and lack of supernatural powers, he helped keep Derek alive long enough to be cured of his wolfsbane poisoning, kept him afloat in a swimming pool after Derek had been paralyzed by Kanima venom, and confronted the feared matriarch of the Calavera Family, Araya with Lydia Martin in order to try to buy Derek's freedom, as the McCall Pack believed her to have captured him. Likewise, Derek has saved Stiles' life as well, with Derek helping to protect Stiles from Peter while he was still an Alpha, and putting his life on the line several times to try to end Stiles' possession by the Nogitsune.
Stiles and Derek's last team-up occurred in Season 4's Smoke and Mirrors, when they helped the newly-bitten Werewolf Liam Dunbar learn control over his transformations on the full moon while they drove to Mexico to save Scott and Kira from Kate Argent. During this time, Derek was gravely wounded after being attacked by one of Kate's Berserkers, which seemed to seriously concern Stiles, though Derek urged him to go in and finish their mission. Afterward, Derek managed to recover from the wounds as a result of his evolution into a Werewolf who can full-shift, and he left Beacon Hills shortly afterward. It remains unknown if the two have communicated since Derek left town.
Derek and Stiles are also known as Sterek, and, less frequently, Halinski, by fans
- Though Derek and Stiles' relationship can be quite antagonistic at times, they have developed a good friendship throughout the series.
- Prior to Tyler Hoechlin leaving the series, "Sterek" was the ship with the most fans in the Teen Wolf fandom.