eager beaver vs doer

eager beaver and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
eager beaver	Yes	No	No	No
doer	Yes	No	No	No

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

Other hypernyms of eager beaver include actor, worker.

eager beaver (noun)	doer (noun)
an alert and energetic person	a person who acts and gets things done