This is exactly how I pictured Thranduil killing a Dragon during the War of the Last Alliance, in my AO3 story: http://archiveofourown.org/works/10838010/chapters/24520668
“All too soon, the Dragon descended, and the glow in its belly was moving up its neck; ready to spit fire. As it swooped low over the hill, Thranduil leaped out from behind the rock, jumped atop it, then made an impossibly high leap into the air, as only an Elf can do. He flipped forward in a somersault to give his sword-strikes more impetus. He then uncurled his body and stabbed the Dragon in its vulnerable underbelly and held on, using the creature’s momentum against it to slice its gullet wide open, thus killing it. But he was not unscathed. The fire that had been building in the Dragon’s gut escaped, and it hit Thranduil dead on. He was too close to avoid it. Even worse, some of the Dragon’s blood had landed on one side of his face.
“Most of his soldiers realized, afterwards their King knew this would happen; he did not expect to survive killing the Dragon. He was willing to sacrifice himself to save the Army, and, in turn, the population of the Woodland Realm, so that it could endure. “A true King is a servant of his people,” King Oropher had always told his son, and Thranduil didn’t hesitate to serve. If there had been any lingering doubt about the ability and the bravery of the new King of the Woodland Realm, they vanished instantly. Thranduil earned the undying love and loyalty of his Army, and all the other Armies of the Free Peoples that were there. When the people back in the Greenwood learned of his deed, they were completely devoted to him. They would follow him wherever he led them; unto death if need be. He truly earned his title as the Mightiest Warrior on Middle Earth.”
