Lol this is basically my favorite character trope ever so I have a few of 'em.
Snitch - Thirteen-year-old savage girl living in a burrow near a marsh with her doofus older brother. She hates everything, eats everything, can and will bite your hand off, hisses when she's mad, and once took down a fully-grown moose all by herself. You put her in front of Satan himself and she'll kick his shins.
Mike - This is only him during his late teens…..he was going through a rough time back then. His general philosophy was "I don't care who you are, I can kill you as long as you're in arm's reach." Which was pretty much true. He, a perfectly ordinary human, fought small armies, guys twice his size, immortal beings of evil, and giant shape-shifting monsters. If he got hurt, he walked it off or slept until he felt better. Also he trusted no one and had no friends :( Luckily he's in a much better place these days.
Crash - One of the aforementioned giant shape-shifting monsters. To be fair, most of his species falls into the "too angry to die" category. Although you could also argue that they're really just too dumb to die lol. Crash has survived these things: a shattered leg at age eight, a fight with a bulldozer, a tree falling on him, a huge avalanche during a storm, a head-on collision with a cathedral window, getting beat up by his crazy sister, and more infections/food-poisonings/muscle injuries than he can count.
Honorable mention: Crash's dad Destroy is even bigger, dumber, and angrier. He got drafted, ate some soldiers, got thrown in monster prison, broke out, started a massive wildfire, ran off with his wife, had kids, got tracked down by the army, flipped a tank, and saved his family. Raised his kids to kick butt and lived to the ripe old age of fifty-two (which is crazy old for his species).