Devil's Snare is composed of a mass of soft, springy tendrils and vines that possess some sense of touch. Devil's Snare uses its creepers and tendrils to ensnare anyone who touches it, binding their arms and legs and eventually choking them

The harder a person struggles against Devil's Snare, the more faster and more tightly it binds them; if they relax, it will not kill them as quickly. Devil's Snare prefers a dark, damp environment and shrinks away from fire, so a well-placed flame spell such as "bluebell flames" will drive it away from its victims.
First year students at Hogwarts learn about Devil's Snare in Herbology classes.