Higemaru Makaijima/Dokuro Island

Pirate Ship
You will find the Pirate ship with the key to the Dokuro Island gate off the East coast of Hebi Island, just below Cuck Island. Once again, you will be presented with a brand new layout for the ship, and the number of pirates you must defeat in order to face the captain will increase to 30. Dokuro Island is distinct from all other island, as you will find the key is not enough to enter the island. If you attempt to approach it after collecting the key, you will be turned away after being informed that the island is sealed. In order to break the seal, you must visit Cuck Island once more, and return to the screen beyond the boss fight location with the lamp that you obtained in the basement of Hebi Island. If you do, the two candles beyond the old man will be lit, and the seal on Dokuro Island will be lifted, allowing you to set foot on the island.

Dokuro Island
Throughout the game, you may have heard many references to a "Death Island" although no such island exists. It won't take a lot of time on Dokuro Island for you to realize that this is what they were talking about. In fact, Dokuro is Japanese for "skull," and indeed the island is in the shape of a skull. Once the seal is broken, and the key is in your possession, you will start out on the north coast of the island. Throughout the island, you will find pools of red liquid. Falling in these pools will cost you a terrible 5,000 life points, so do not walk near the edges. You may find, once you begin to explore, that the west half of the island is oddly difficult to approach. There is only one means of reaching it: through a secret passage at the very bottom of the island. So you will have to make your way from the top to the bottom of the east half of the island before venturing up the west half. It is a little faster to travel to the left of the east "eye socket," although it's safer to travel along the right side. You will also find more treasures hidden along the east coast, but they lie in out of the way places.

In addition to the deadly effects of the red liquid, you will have to watch out for the island's native "life," most of which is undead. Killer Snakes are snake skeletons that dart around the ground, while Skull Flies are floating skulls that fly in circles around a fixed point. While these two enemies are dangerous, they are nothing compared to the Tree Eyes which disguise themselves among regular trees and come to life when you get to close. Once awake, they slowly hover to your exact location, and when they are on top of you, they are extremely difficult to shake off without leaving the screen entirely. Don't let them get too close to you. You will have to lure one out of hiding in order to discover and access the secret passage that will give you access to the west half of the island, and the boss who awaits you near the top. Once you are on the other side, you must climb up to the boss' location on the west coast of the island.

Boss fight
The boss of Dokuro Island is a lich known as the "Zombie Giant." He appears tougher than he really is. He hovers over a fixed location near the center of the top of the screen, and no matter how he flies, he never strays far from the spot. He also throws a never ending supply of his own eyeballs at you, but they will not stop the path of the skulls you throw, so you can easily throw past the eyeballs and beat him. His only vulnerable spot is the head on top of his body, so concentrate your throws near the center of his flight path, and the skull should inevitably hit him in the head. Once he is defeated, you can travel to the screen above and collect the chart, a valuable item for translating the strange foreign words that you have come across on the various monoliths.

After collecting the chart, you can shortcut your way back to the entrance of the island, by staying on the west half of the island, and traveling along the left side of the west eye socket. Continue to climb up and eventually, you will find the source of all the red liquid oozing throughout the island; a giant disembodied heart that is still pumping. One screen to the right, you will find a set of four skulls, one of which is hiding a hole which will transport you back to the entrance.