scratcher vs doer

scratcher and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
scratcher	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of scratcher; that is, doer is a word with a broader meaning than scratcher:

Other hypernyms of scratcher include actor, worker.

scratcher (noun)	doer (noun)
a device used for scratching	a person who acts and gets things done
a person who scratches to relieve an itch
a workman who uses a tool for scratching