Watch The World’s Grossest Creature Eat Fish Tongue
From "NOVA's Gross science: The Tongue-Eating Parasite" by PBS on YouTube

You thought you only had to worry about whether the fish you’re eating is really what you ordered. NOVA has a new short video that explains that even if the snapper you buy is correctly labeled, it might still have a tongue-eating parasite living inside its mouth:

I had one pressing question after watching that. Might I really run into Cymothoa exigua the next time I’m at the grocery store? It seems so. Seafood processors do perform some inspections for parasites, but can’t find and remove everything they see, according to this Sea Grant California guide. And of course you could always encounter some Cymothoa exigua friends if you catch your own fish dinner.