If we're ranking shit by smell, then carnivores are the absolute worst, omnivores are a close second, and herbivores are a distant third. Everything excreted by a big cat (Lions, Tigers, etc.) is so so smelly, and it seeps into everything. You can smell the big cat zookeepers as soon as they walked into the room.

Omnivores excrete stuff that is almost as smelly as those cats, but at least it's familiar. Maybe that makes it worse. Admit it, your own farts are never as offensive as someone else's. Raccoon poop, especially the dried out and dusty kind will straight up kill you though, so watch out for that. Primate fluids can pretty risky too because of their similarity to us.

Herbivore shit is fucking perfume compared to the others. Horse shit doesn't actually smell that bad at all unless there is something wrong. The ammonia from their piss is something fierce and awful though. Mucking horse stalls is like scooping a litter box for a cat the size of a horse, but the actual shit is the most pleasant aspect. Elephant shit is the most pleasant shit I've ever had the pleasure of shoveling. It's like wet dead grass with a hint of musk.