The Internet has fried my brain. All I can think of when I hear the phrase "bad dude" is the old meme spoofing the intro to Bad Dudes for NES:

That bad dude is called Dunkleosteus.

That’s a bad dude

It's always great to see a big Dunk.

Oh the annoying guys to hunt in Dave the Diver!

Somebody made a STL you can print

https://cults3d.com/en/3d-model/various/dunkleosteus-lordtrilobite

Uh, listen Bro. All that sushi i ate before? Just a misunderstanding, right?

Soooo many fishes could fit that description, but I’m glad my dude found his bad dude. Like, dude.

It looks like Brak.

There were also other nice guys

And those which still exist

I believe it's called a Coalacanth

I'm not a biologist and this may be a stupid question, but are this monster's eyes armored? Armored eyeballs?

What a bonehead

it's in animal crossing (new horizons?)