Something that is old or rusty looking is considerated scratchy. It can be a homeless person or a pure nerd or just one at heart, Huckleberry Finn is said to be the scratchiest book of all time.
That old man'schesterfield was rather scratchy.
I slept in and am looking rather on the scratchy side today.
Look at that scratchy boy's hair.
A scary movie, typically a horror movie. Although the term may be used to refer to scary movies more generally, a "scratchie" refers to a scary movie with a evil character that scratches.