Eldmor

Eldmorem are dimension-traveling destroyers that arose in a distant parallel dimension. Half living, half automaton, eldmorem lie like cysts between dimensions, only waking from the sleep of ages when disturbed. When that happens, a lone eldmor stretches to its full 200-foot (60 m) length and attempts to trace the traveler’s dimensional trajectory back to its plane of origin. If it finds the location, it enacts half-forgotten instructions received millennia earlier and attempts to destroy everything it finds.