The hornhog split off from the planthog. Unlike its ancestor, the hornhog's body is much more heavily built than its ancestor, they have become slightly more aggressive, and it's third hoof-claw has become a spur which is used to kick and stab predators behind it. The front part of its snout has also developed two small dimples, which act as shock absorbers. This helps them quickly recover from ramming at other hornhogs. The reason why it is called the hornhog is because of an obvious evolution, which are its two wooden horns on its head.
Another big change it went through is that is became more vegetarian, though it still eats butcher worms on the occasion. Since it also eats yellow firegrass, its body has become somewhat heat resistant. It also eats barbarian sauceback kills. It watches and waits for the barbarian sauceback to kill and eat its prey, then the hornhog eats whatever is left of the carcass.