Hoop snake — the cryptid my granddad swore on, Appalachia/Ozarks

This isn't a monster-monster, it's the folklore that won't die, and my own family is a data point. Hoop snake: bites its own tail, forms a wheel, and ROLLS downhill after you faster than you can run. Got a venomous stinger in its tail — strike a tree with it and the tree dies overnight, swells up an……