Super Gargoyle or King Drake is the boss of Dragon Island.
The dragon boss that you encounter here is slow but direct. He will fly over to your current position, stop and breath a large jet of flame. Then he will resume his chase and repeat the process. If you have the wings when you arrive, this boss is fairly easy to beat. Lure him to one side of the screen, and attack him from the other side until he moves again. If you don't have the wings, you'll need to provide yourself with an escape route when he begins to fly toward you. Try to lure him to a location somewhere just above the ground so that when he stops, he won't be a threat to you, but you can be a threat to him.