blowfish, n. — Green’s Dictionary of Slang

blowfish n.

[SE blowfish, a puffer, a saltwater fish that is ordinarily thrown away by fishermen]

an insignificant, unpleasant person.

1995		Big Punisher ‘’95 Freestyle’ 🎵 They pack a cap but won’t attack a blowfish.
2001		Scheck, Neufeld & Dwyer Actual Innocence 136: ‘We’re going to give Robert Miller the needle in this deal,’ said Elliott, ‘He’s just blowfish.’.