odd fellow vs odd fish

odd fellow and odd fish both are nouns.

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

As nouns, odd fellow and odd fish are synonyms defined as:

odd fellow and odd fish: someone regarded as eccentric or crazy and standing out from a group

Other synonyms of odd fellow include kook, odd man out, queer bird, queer duck.

odd fellow (noun)	odd fish (noun)
someone regarded as eccentric or crazy and standing out from a group	someone regarded as eccentric or crazy and standing out from a group