From cat +fish. Likely so named for its prominent barbels like a cat's whiskers. Compare West Frisiankatfisk(“catfish”), Dutchkatvis(“catfish”). Compare also GermanSeekatze(“catfish”, literally “sea-cat”).
“You don’t see catfish that big anymore, except in Chernobyl […] Nobody fishes there anymore, so the catfish thrive. They’ve gotten really enormous, some even twelve or thirteen feet long. They’re bottom-feeders, and apparently the mud still contains a lot of radioactive particles, but the catfish don’t seem to mind.”
The meat of such a fish, popular in the Southern U.S. and Central Europe.
From the 2010 documentary Catfish, supposedly inspired by the practice of fishermen keeping cod active by storing them with catfish (see sense 1) which nip at their tails.
catfish (third-person singular simple presentcatfishes, present participlecatfishing, simple past and past participlecatfished)
(Internet,slang,transitive) To create and operate a fake online profile to deceive (someone).
2013 January 17, Mary Pilon, “In Te’o Story, Deception Ripped From the Screen”, in The New York Times, →ISSN:
Getting catfished is when someone falls for a person online who is not necessarily real. It can involve pictures, phone calls, social media profiles, text messages, e-mails and even phony friends or family members.
2014 January 16, 12:17 from the start, in Cooperative Polygraphy (Community), season 5, episode 4 (TV), spoken by Troy (Donald Glover), via NBC:
[to Abed] You made a profile for a fake dude and lured her into an online relationship. [to Annie] He's catfishing you.