There’s a (relatively*) pint-sized tyrannosaur fossil that’s been in the science news lately, and because it’s a precursor to the more famous Rex, it’s been given the name Moros intrepidus. That translates, apparently, to “harbinger of doom”. Let that name sink in a moment.
Of course, “tyrant lizard king” is pretty hardcore itself.
And among still-extant animals, there’s the untoppable Vampyroteuthis infernalis, “vampire squid from hell”. This is objectively the most metal name of any living creature, and you can fight me on this.
*seriously, everyone is calling it “tiny” and “deer-sized”. I don’t know about you, but if I came face to face with merely “deer-sized” tyrannosaur, I wouldn’t be thinking thank goodness, it’s only a hundred seventy pounds.
I’m pretty sure I noted this in some previous thread years ago, but the full scientific name of the Western lowland gorilla (a subspecies of the western gorilla) is Gorilla gorilla gorilla. (Not so much “metal” as “utterly charmingly goofy”.)
I like the scientific name of the highly venomous Bushmaster: Lachesis mutus. Lachesis is the Fate who measures out the length of your thread of life, while mutus means silent. So the name means “silent bringer of death.”
Mus musculus sounds like it ought to be a pretty ripped critter, but musculus is actually the diminutive of mus, so it’s just ‘mouse, tiny mouse’. Maybe shoegazer? Twee?
Nitpick: you have the name in the wrong order (and capitalized it wrong) - it’s Ursus arctos horribilis. (Same translation, though.)
For extant (and non-dubious) species, it’s hard to beat V. infernalis, but there’s some good ones among the extinct dinosaurs, like Stygimoloch spinifer, the Thorny Devil of the River Styx. (Which may or may not have been juvenile Pachycephalosaurus, which is a much less metal name.)
Which reminds me, there’s also Dracorex hogwartsia (“Dragon King of Hogwarts”, so maybe fantasy metal), another one that might be some developmental stage of a Pachycephalosaurus.
I just heard this one the other day. It’s kind of the opposite of metal, though. A turkey vulture is Cathartes aura, purifier of the area. I guess it’s better for the birds than anything else it could have been, like “cleaner of death” or something.