"Speed: Unknown. Size: Unknown. The unholy offspring of lightning and death itself. Never engage this dragon. Your only chance, hide and pray it does not find you." ―Hiccup, when reading the Dragon Manual.
Night Furies are very intelligent and stealthy dragons.
Night Furies are jet black and are small in size. They have very large wings compared to their body allowing this dragon to fly faster, longer and farther than any other dragon. They have yellow eyes with pupils that contract when they are angry or scared and round pupils when they are happy or exited. They also have a two sets of sharp retractable teeth. They depend on their own tail wings for flight.
Night Furies are amazing fighters. They use their incredible explosive fire to damage any unlucky foe that gets in its way. A Night Fury also uses the dark-lit sky as cover when attacking enemies. Night Furies use their amazing speed and agility to dive-bomb and shoot fire at their targets at high altitudes. A Night Fury's flames contain oxygen and acetylene and will explode upon impact, incinerating anything that gets hit by them. Night Furies, when breathing their explosive fireballs, will always make a sonic-pitched scream. Another thing that is more deadly than a Night Fury's dive-bomb and flame attack is that Night Furies never miss their targets. If a Night Fury cannot see it will use echolocation.