Gravel-chewer

It remains unfinished and untextured, but it exists. This is a gravel-chewer, a hefty omnivore that gets its name from the thick, abrasive grass that it eats. The grass doesn't have a lot of creatures above it on the food chain, because it's basically sawgrass with a nasty tangled root system that doesn't let go of the dirt. So you'll see the gravel-chewer tearing up massive clumps of grass with even more massive lumps of dirt attached, and from a distance it looks like the thing's eating dirt. And yes, it does consume a lot of dirt, but then it's not very picky at all.

It travels in herds and is migratory, and its primary predators are... well, I haven't drawn them yet. It walks on its front knuckles, over which have grown thick hoof-like skin-pads; its back feet just have the pads. It can jump, and run, and crush the bones of small animals with its teeth. It uses its impressively thick skull and horns for mating displays and self-defense, and has also been known to punch the crap out of smaller things that get in its way.

Obviously, I gave it some horse-like structure, but I also looked at gorilla, hyena and lion references too.

It needs a heavier tail, for balance.