The "penis fish" is a marine creature called the fat innkeeper worm. It's not a fish but looks like a, well, you know! They live in sandy beaches and stick their head out like that, making them quite unusual and funny-looking.

In South Korea, you can try the "penis fish" for… pic.twitter.com/QkRqmqIzBe

— Untalented Guy (@STEMbySum) October 4, 2023