Skull Island
From Monkey Island wiki
Skull Island is the third new island featured in The Curse of Monkey Island. It's a small island off the coast of Blood Island to the east. Surrounded by an endless ocean mist, it is nefariously difficult to reach. The ghostly ferryman the Lost Welshman continues to row between the islands after the light of the Blood Island lighthouse was smashed. The island is the home of the smuggler King Andre and his henchman Cruff. Guybrush must acquire the diamond from the Goodsoup family Wedding Ring from Andre in order to lift the curse from his fiancée Elaine. At the top of the island one can find Effete LaFoot operating a winch to lower people down to the cave.
Though Skull Island is thought to look like a skull, it is revealed to the player that the island actually has the appearance of a duck. Guybrush even comments: "It should be called Duck Island". The Welshman insists that one must "squint and turn [one's] head a bit to see the skull". Guybrush continues to point out that if one actually does that "it looks like a bunny". This is a reference to the famous rabbit-duck illusion, a kind of ambiguous drawing that causes the brain to be uncertain if the drawing illustrates a rabbit or a duck.
