As Hiccup, Gobber, and Fishlegs test out the Gronckle iron formula, Tuffnut shows up to report to everyone he was bitten by a wild unknown dragon. Later, Gobber tells the riders about the mysterious Lycanwing that turns people into dragons with its bite, and thanks to Snotlout, Tuffnut now thinks he is the latest victim.
Tropes:
- Aw, Look! They Really Do Love Each Other: Ruffnut spends the whole episode worried about her brother and pissed at Snotlout for tricking him. Snotlout would come to regret getting on her bad side.
- Becoming the Mask: Tuff eventually reveals (to the chicken) that he was just faking that he believed Gobber's story, but after overhearing Hiccup talking about finding evidence of a real Lycanwing, Tuff begins to believe the story for real.
- Call-Back:
- Fishlegs and Gobber have figured out the formula for Gronckle Iron, three years after the happy accident.
- The Dragon Eye lens that Gustav found leads Hiccup, Fishlegs, Toothless, and Meatlug to more lenses on Lycanwing Island.
- Chekhov's Gun: The Dragon Eye lenses that Gustav and Hiccup found earlier. Hiccup and Fishlegs learn that the fake Lycanwing is composed of them.
- Foreshadowing: When Ruffnut tries to identify the dragon that bit Tuff, she finds that none of the bites match. At the end, Snotlout reveals it was a wolf bite.
- Genius Ditz: Tuffnut remembers that sea snakes are venomous long before his sister does, after Snotlout is bitten.
- He Who Must Not Be Seen: The wolf, it's only seen while in a sack and when it escapes, the camera switches to its point of view.
- Humiliation Conga: Ruffnut forces Snotlout to get bitten by many kinds of dragon and a venomous sea snake, partially to find out what really bit Tuffnut, and partially to get back at him for seemingly convincing Tuffnut that he's turning into a dragon. And at the end of the episode, Snotlout gets bitten and later mauled by a wolf.
- Large Ham: Tuffnut at first pretending and then believing that he is going to change into a Lycanwing.
- Leap of Faith: Tuffnut plans to do one at the climax to trigger a dragon transformation. Ruffnut is freaking out, understandably.
- Oh, Crap!: Ruffnut when she finds Tuffnut and Chicken are missing.
- Our Werebeasts Are Different: Lycanwings are said to have a bite that turns people into human-dragon hybrids on full moon nights.
- P.O.V. Cam: At the end, we see things from the wolf's POV as it mauls Snotlout.
- Red Herring: Hiccup and Fishlegs do find Lycanwing Island, but the only important things there were new parts for the Dragon Eye.
- Scary Shadow Fakeout: In the cave at Lycanwing Island, the rocks have been arranged so that any light shined down the tunnel will make the shadow of a giant dragon.
- Suddenly Voiced: Chicken starts talking with a seductive female voice at the height of Tuffnut's insanity.
- Take That!: DreamWorks' arch rival Disney once had an animated series about humans who could turn into dragons — this episode mocks the concept to death. Gobber's description of the Lycanwing as "a red, black-eyed dragon" even matches the description of Jake Long's dragon form!
- Talking Down the Suicidal: Or rather, talk down the teenager who thinks he's going to change into a dragon. Ruffnut tries, but manages to only stall long enough for Hiccup and Fishlegs to reveal that the Lycanwing was a decoy.
- Unwitting Instigator of Doom: Snotlout only meant to play a prank on Tuffnut, but he didn't expect Tuff to become Too Dumb to Live.
- Weakened by the Light: A symptom of the Lycanwing curse; upon learning this, Snotlout points out that Tuffnut can't look directly towards the sun.
- What the Hell, Hero?: Ruffnut is very angry at Snotlout for tricking her brother and possibly endangering him, and she lets him know.
