The Skull Island Snapper, Inimicostium insula, is an unusual, semiaquatic, carnivorous, snapping turtle-like tortoise from the swamps of Skull Island. It measures 2-3 feet long.

A variety of tortoise that has only recently (in evolutionary terms) exchanged a purely terrestrial existence for life mostly in the water, Skull Island’s resident snapping turtle-like turtle is not a true chelydrid at all. The most obvious feature of the species’ land-living past is its shell, which, unlike most other semiaquatic testudinatans, is high and domed instead of flat. The carapace is tall and knobby like some Asian tortoise species (which may well be its ancestors) but the head and face are similar to the unrelated New World snapping turtles.

The species has rejected the herbivorous diet of its terrestrial cousins in favor of a menu rich in meat. Skull Island snappers are fiercely predatory. Being slow moving, they favor ambush predation. They wait hidden in the reeds and mud or in shallow water in order to drag birds, like cormorants, and other unsuspecting prey, like baby Ligocristus, to their watery doom.

Predators of their own include Turturcassis.