Bonehead Island is a location in Paper Mario: The Origami King, an island located in the Great Sea. It is found around the southeastern corner of the sea, just outside the fog. As such, it can only be explored after retrieving Captain T. Ode and his submarine from Musée Champignon in Toad Town, making it one of the first islands to be visited in the game. A coffee shop is found here, as well as a Snifit peddler. This level shares many similarities, such as an island with a giant skull-shaped rock and a puzzle involving lighting torches, with Fortune Island from Paper Mario: Color Splash.
When Mario, Olivia, and Captain T. Ode arrive on the island, Olivia describes it as spooky, notating that the large, hollow skull in the middle of the island appears to be staring at them. The captain tells them to explore the island, claiming there are secrets within. Mario must get off the boat onto the dock and head toward the skull. There are two Not-Bottomless Holes in the base of the skull, as well as one in the wall to the left and one in the ground to the right. Heading left, there is a Snifit peddler, a Fire Flower on the campfire, and two barrels containing confetti. Off to the right and down on a ledge, there is a ? Block containing a Shiny Ice Flower and a Not-Bottomless Hole in the wall. Patching it reveals a door to a coffee shop, where Mario can purchase a "Morbid Mocha" to initiate a conversation between a Dry Bones and a Bone Goomba.
To get into the skull, Mario must enter a hole on either the right or left side of the skull. If Mario heads to the hole on his left side of the skull, he can drop down onto a ledge to find a crumpled Toad. As thanks for rescuing him, the Toad gives Mario the location of a sunken treasure before joining the Snifit peddler. Inside the skull, there are three rooms. Two rooms have a nearly identical setup, while the middle room simply has a small skull in the middle with a flame in its left eye. This indicates Mario must hit the pillars in the other rooms to make them symmetrical. Doing this makes a button appear in the middle room, which Mario must hit to raise the skull and reveal a set of stairs.
Up here, there are a few barrels and crates containing a confetti, as well as a treasure chest containing Bonehead Island's only collectible - Collectible Treasure #74: Submarine "Marino". Mario can then head south to exit this area and reach the outside, at the top of the skull. He can then slide directly down, reaching a small niche with a backwards Toad statue. Hammering it turns it forward to reveal a message: "If you seek paradise, gather the three orbs on Diamond Island". As Olivia ponders what this means, a massive fan appears in the background, blowing away the fog, allowing them to easily access the surrounding islands. The statue then reads, "Seek and ye shall find... Come, follow me to paradise...", prompting them to head out to the purple streamer.
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