That's what his species is called. He's a Night Fury. They can be terrifying, if you've crossed one. [Toothless is different, though, in a way. He's much more used to people than Hiccup figures any other Night Fury would be. It's easy to forget that he can be lethal, when normally he's so playful and happy.]

Yeah! [He's excited, but hushed, following Toothless closely down the tunnel, one hand on the wall until it starts to widen.] It's possible we're the first people here in- maybe ever. Anything could be up here. Treasure, or- or magic, or cave paintings. Lost knowledge.