Skarbone

It scavenges the desert's grim leavings, picking bones clean and selecting the best-fitting skull to wear, discarding and upgrading as it grows. The bone-armor hides it among the actual carcasses of the bone-fields, so that a scattering of skulls may include one that is watching you. Timid by nature, it relies wholly on that disguise and on freezing still, and a startled Skarbone abandons its cover and flees in a mad clattering rush, trailing borrowed bones and its own thin, rattling cry of alarm.