You pay a premium for its pedigree, but Michelin's Mud 3 is still the daddy of all things dirty and dark.
For a start, the tubeless carcass means you can run it softer than most 2.2in tyres without popping on the first impact. It'll work its long, super soft compound spikes through gaps in the most random rock and root sections, too.
The staggered tread means they've always got a spike biting - however much they're leaned - and they corner like they're on rails when everything else is already letting go. They're spaced enough to stay clean even at low speeds, too.
These tyres do scrabble and wander on firmer sections, though, and they're tortuously slow rolling, so it'd need to be proper wet and stupid steep to make them worth their high price.