A Giant Skeleton is a feature that can be found in the Aquis realm.
A giant skeleton lies in one of the tunnels which leads to the conveniently named: Skeleton Sub-station. As it is submerged in deep sand, and lacks any flesh and muscle, it is hard to tell what the creature would look like alive. Its head is visible, however, and looks similar to that of a prehistoric creature from Mortalis, the Tylosaurus Proriger. It is possible that this monster could be a "Leviathan" that Queen Aino spoke of to Jen, however, she also commented that Leviathans were a type of Undine God.