Scratcher

noun

1. One who or that which scratches.
2. An instrument for marking trees, usually a hook-like gouge fastened to a flat elliptical iron hoop with wooden handle-plates on the opposite side from the gouge. Also called bark-blazer, cruiser's bark-blazer, tree-scribe, and bark-gouge.
3. One who, or that which, scratches; specifically (Zoöl.), any rasorial bird.
4. Someone who scratches.
5. A piece of equipment used to scratch part of the body to relieve an itch.