- Valka's mask is a bit more than a tad creepy. Her introduction in the clouds and the way she would move about when in the cave is also unsettling. It's understandable for someone who's lived only with dragons for 20 years with no human contact but still, no less creepy.
- Toothless's cold, reptilian eyes when he's controlled by the hypnotic song of the Alpha.
- "No dragon can resist the Alpha's command. So he who controls the Alpha... controls them all. Witness true strength... the strength of will over others. In the face of it... You. Are. Nothing."
- The fact that Toothless, lovable, loyal, Toothless is mind controlled so casually into attacking Hiccup, only for his blast to kill Stoick.
- This lets us see why Night Furies are so feared. All other dragons have dangerous, but seemingly survivable forms of fire breath. Toothless' blasts, when he is serious, are a One-Hit Kill even for a viking of Stoick's size.
- The blurry red vision of Hiccup from Toothless' perspective when Toothless is under the control of the Alpha and Hiccup tells Toothless, "Stop! Snap out of it!"
- From Toothless' POV: being mind controlled into killing someone you love, and then having no recollection of it afterwards. While he ended up killing Stoick instead, it was still someone he cared about, and all the same it remains a powerful mixture between this and Tear Jerker trying to imagine how Toothless would have felt like had he really woken up to find that he just killed Hiccup.note
- The lead up to all of the above mentioned is also mixture of both this and tear jerking; Hiccup throughout the entirety of the film wants to confront Drago so he can convince him that dragons are kind creatures, just like he had successfully done before with Astrid, his dad and his entire tribe, and thus were confident it would work again. Finally seizing the much awaited opportunity, he gets retaliated with "No!... Let me... show you!", Toothless mind controlled into attacking him and ending up instantly killing his father.
- Drago and his Alpha Dragon are walking Nightmare Fuel. Even in a setting full of battle-hardened Vikings, Drago exists in a class by himself owing to his being absolutely Ax-Crazy.
- Drago's face is covered is scars and is missing one of his arms which has been replaced by a metal one. We are treated to seeing the stump not once, but twice.
- Drago's Alpha dispatches Valka's Alpha by impaling it on its tusks. It cuts away just a split second before the deed, but you can feel it.
- The Alpha's call to brainwash the dragons after the other Alpha is killed. Dragon's army swells to massive sizes and you know Berk is next and there's nothing Hiccup can do about it. It then proceeds to destroy Berk, very nearly succeeding.
- Stoick's flashback to how Drago killed many island chiefs with his dragon army for refusing to pledge allegiance to him.
- If you listen closely enough to Stoick's narration, you'll hear Drago speaking almost in-sync to what Stoick is saying. This moment is so traumatizing to Stoick, he remembers it word-for-word.
- During Stoick's funeral, Valka mentions to Hiccup that he "Came too early into the world". Hiccup was born premature. Even though we all know that Hiccup pulled through, can you imagine what his parents were going through? Yes, Valka told Hiccup that Stoick believed he would be okay, but could you imagine parents having to possibly face the possibility of their first child dying, especially given the time-period and harsh conditions in Berk?
- Spitelout is briefly seen being the stand-in chief of Berk when Drago attacks. Drago makes the Alpha blast ice breath right on top of the gathered group of vikings, including Spitelout. He is not seen for the rest of the movie. Thankfully, the next movie shows he is fine.
Nightmare Fuel / How to Train Your Dragon 2