The Moles, also known as the Body Moles(体内モグラ, tainai mogura) is a group led by Ouni on the Mud Whale. They repeatedly break the rules of the Mud Whale, and thus are so frequently imprisoned in the belly of the ship that they gained their name. Their goal is to see the world beyond the Mud Whale.
The Moles were originally just a group of Nibi's friends. However, after Nibi and Ouni were imprisoned together in the belly of the ship after fighting, Nibi learns of Ouni's desire to see the outside world, and promises to help him. In the coming years, Ouni gradually became the leader.
Eventually, the moles became split into two groups: the one lead by Ouni, and another group that admired Ouni but were unable to get along with Nibi, which was led by Shikon and Shikoku.