Caradune

It buries its whole bulk beneath a false dune of its own making, sculpting the ridge over hours until nothing distinguishes it from the real hills around, and then it simply waits, sometimes for days, for prey large enough to be worth surfacing. When it erupts, a whole hillside seems to stand up and strike. It carries its water internally against long droughts, metabolizing fat from its ridged back, and an old Caradune can outlast a dry season that kills everything else on the flat, emerging gaunt but victorious to bury itself and begin again.