an odd/a queer fish

odd fish

Someone deemed strange by others. No, I didn't invite Joey—he's an odd fish, if you ask me. You can't say weird stuff like that, unless you want everyone else to think you're an odd fish.
See also: fish, odd

queer fish

Someone who is very strange. Primarily heard in UK. Everyone could tell he was a queer fish as soon as he walked into the party with his mismatched clothing.
See also: fish, queer
Farlex Dictionary of Idioms.

an ˌodd/a ˌqueer ˈfish

(old-fashioned, British English) a strange person: He’s an odd fish. He’s got a lot of very strange ideas.
See also: fish, odd, queer
Farlex Partner Idioms Dictionary

queer fish

n. a strange person; an aloof person. She’s a bit odd. Sort of a queer fish.
See also: fish, queer
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • odd fish
  • ask (one) over
  • ask over
  • biggity
  • cocky
  • cocky as the king of spades
  • (as) cocky as the king of spades
  • ask back
  • case
  • barber