Skin tags are usually oval flaps of tissue that hang from the skin on a tiny stalk.

The entrance, or 'mouth', of the trap is a circular or oval flap whose upper half is joined to the body of the trap by very flexible, yielding cells which form an effective hinge.

An oval flap of skin and flesh was dissected free and was drawn back, exposing the gleaming bone beneath, and again David's flesh crawled as though with living things, as the surgeon took up a drill that resembled exactly a carpenter's brace and bit.