Reaper Leviathan remains can be found on the floor of the Inactive Lava Zone, and within the Mountains corridor. They are either found as whole skeletons, or just skulls. The Reapers came to rest in these locations in recent months due to the dwindling food supplies of the Inactive Lava Zone, which forced the Sea Dragon Leviathans to hunt elsewhere to support their massive food requirements. As a result the Sea Dragons have recently started coming out of the lava zones to hunt Reaper Leviathans.
Data Bank Entry
Reapers are ill-suited to high temperature environments, suggesting this creature was forced down into the active lava zone by conditions outside its control.