odd fish vs doer

odd fish and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
odd fish	Yes	No	No	No
doer	Yes	No	No	No

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

odd fish: someone regarded as eccentric or crazy and standing out from a group
doer: a person who acts and gets things done

Other hypernyms of odd fish include actor, worker.

odd fish (noun)	doer (noun)
someone regarded as eccentric or crazy and standing out from a group	a person who acts and gets things done