Teen Wolf Wikia
Teen Wolf Wikia

"This particular lichen is called letharia vulpina-- 'wolf lichen.' They'd put out pieces of meat with crushed glass and bits of the lichen in it. The glass perforated the intestines of the animal so the vulpinic acid could reach the internal organs faster."
"What did you do to my wolf?"
"Well, I didn't poison him with lichen... But I did give him a powerful paralytic agent. The same one I put on that jar."
"I guess we both know a few things, Ikeda-san. Born out of the blood of a Nogitsune, this lichen is quite special. More powerful than you know."
"What-what are you going to use it for?"
"There's a Fox hiding inside a teenage boy... and I'm going to poison it."
Alan Deaton and Ikeda about letharia vulpina

Letharia Vulpina is the nineteenth episode of Season 3 and the forty-third episode of Teen Wolf.


Scott and the others try to prevent a disaster. Lydia and Allison seek out an unlikely teacher.


Deaton retrieves a poisonous plant that will aid him in defeating the Nogitsune. Derek and Chris Argent are arrested by Agent McCall for the murder of Katashi after being framed by someone. Stiles, who is still missing, reappears in the school basement. After finding a map of the cross-country trails, he, Scott, Aiden and Ethan realize that the path has been booby-trapped by Stiles. The boys are successful in stopping the runners from being injured but Coach Finstock is shot with an arrow. Allison and Lydia seek the aid of Peter Hale. He asks for Lydia's help in finding the memory that his sister took away from him. Lydia discovers that Peter is a father. The Oni, attack Stiles, Scott and Kira at the animal clinic. They manage to escape but Stiles—still possessed by the Nogitsune—knocks Kira unconscious and tortures Scott with an Oni ninjato until Deaton returned and suppressed the Nogitsune's influence on Stiles with letharia vulpina.


Main Cast[]

Supporting Cast[]

Guest Cast[]


  • It is stated by Melissa McCall that Stiles has been missing for two days, which confirms that there was a time jump of almost 48 hours between the chaos caused by the live wire at the hospital (between the end of Riddled and the beginning of this episode) and when Melissa, Scott, and Allison visited Isaac in the hospital.
  • This episode marks the first "international" episode of the series when Alan Deaton travels to Japan to seek out a rare lichen known as letharia vulpina to neutralize the Nogitsune.
    • Additionally, he goes to the home of Ikeda, the son of the Yakuza leader who was possessed by a Nogitsune during Chris Argent's first gun deal twenty-four years prior, and who is the owner of the home with the Japanese garden where Argent helped save the life of Katashi and the other survivors. This event was seen in flashbacks in Silverfinger.
  • Argent and Derek are framed for Katashi's murder by Nogitsune/Stiles and are arrested by Rafael McCall. Katashi was last seen in Silverfinger.
  • This episode marks the first time Stiles has killed someone when he murders Katashi and causes a bomb explosion at the Sheriff's station that killed several deputies. However, since he was possessed by the Nogitsune at the time and was not in control of his body, it technically does not count as intentional murder, though Stiles will continue to carry guilt for it throughout the rest of the series.
  • Kira starts to further develop her Kitsune abilities in this episode after she discovers she has superhuman strength (though still inferior to that of a Werewolf), super speed, super agility, an intuitive proficiency in combat, and the ability to control and absorb electricity and foxfire. Another new development was that, when Kira was absorbing the electricity, her irises glowed an orange-gold color.
  • It is revealed that Noshiko Yukimura has been summoning the Oni demons from the Nemeton by sacrificing her Kitsune tails, which are represented by black ceramic daggers called kaiken. As of this episode, Noshiko has broken seven of her nine tails to summon the Oni, who were first seen arising from the Nemeton at the end of More Bad Than Good.
    • This episode also marks the first appearance of Kitsune tails.
  • Alan Deaton uses Kanima venom to paralyze Ikeda and his pet wolf Yuki. Kanima venom was last seen in Season 2's Master Plan when Jackson Whittemore used it to paralyze Derek in battle, though it is unknown where Deaton got the venom he used in this episode.
  • Peter Hale confirms that it was his Bite that activated Lydia Martin's latent Banshee abilities and claims she was meant to be his backup plan in case he died as a result of his revenge murder spree in Season 1. He attacked her and gave her the Bite in that season's penultimate episode Formality.
    • Peter also reveals and confirms several more details about Banshees, including the fact that their sense of hearing is enhanced to such a degree that they can hear things at the level of the universe that no other being can, and that their scream can be used not just to announce someone's impending/recent death, but also to clear out their auditory channels in order to allow them to focus on the specific sound they need to hear, the latter of which Lydia first demonstrated in Galvanize while trying to determine where William Barrow took Kira.
  • Malia Tate was mentioned in this episode. She was last seen in More Bad Than Good.
  • Jordan Parrish is revealed to have been an HDT (Hazardous Device Team) technician while he was serving in Afghanistan in the United States Army, which will play a role in many more episodes and will be especially important in Season 5.
    • Additionally, Jared mentions how preternaturally young Parrish looks, the first indication that Parrish may be more than he appears in the series.
  • Kate Argent was mentioned in this episode. She was last seen in Allison's hallucinations in More Bad Than Good, and last seen in the present day in Code Breaker.
  • William Barrow was mentioned in this episode. He was last seen in Galvanize.


  • The title refers to a specific strain of lichen, or moss, known as letharia vulpina, or "wolf lichen." It is commonly used as a poison by mixing the lichen with raw meat and pieces of broken glass to cause the vulpinic acid to enter the bloodstream of the fox, coyote, or wolf who eats it and kills them. The specific letharia vulpina that is found by Alan Deaton in Ikeda's garden was born from the blood of the Nogitsune who possessed Ikeda's father, the Kumicho of the Japanese Yakuza clan who had an arms deal with Chris Argent in the late 1980s, making it powerful enough to use to temporarily weaken the Nogitsune possessing Stiles Stilinski.
  • The Nogitsune demonstrates that he has the ability to absorb pain, just like Werewolves can, only to a much more powerful degree, which confirms what Katashi and the Nogitsune have said about Void Kitsune feeding on chaos, strife, and pain. The Nogitsune used this ability to siphon all of the pain that Scott had absorbed throughout the day from Isaac, Coach Finstock, and a dying deputy who was injured in the explosion at the Sheriff's station.
  • In this episode it is revealed that Malia Tate is the biological daughter of Peter Hale. Lydia discovered this information after using her Banshee abilities to listen to the memory inside Talia Hale's claws.

Body Count[]



  • "Hold On" by William Fitzsimmons
    • Scott and Melissa discuss Stiles before making plans to visit Isaac in the hospital. Sheriff Stilinski gets a text from Stiles telling him not to look for him.
  • "Renegade (Radio Edit)" by DANK
    • During cross-country practice, Kira realizes that one of her Kitsune abilities is super-speed and is amazed when she easily laps Danny, who is the fastest human runner on the team.
  • "Dreaming of You (Svenson & Gielen Remix)" by Thrillseekers
    • Ethan tackles Danny in the preserve and makes out with him. Kira runs so fast that Scott has to leap in the air and spin them both around just to stop her.
  • "2 Thingz" by Basecamp
    • Lydia and Allison go to Derek's loft to get help from Peter regarding Lydia's Banshee abilities
  • "Apple Pie" by Cameron the Public
    • After being shot with an arrow at cross-country practice, Coach panics and tells Stiles, Scott, and Ethan to pull out the arrow in his stomach


See also[]