Hammelhorns were large, shaggy grazing animals with thick, curved horns. They were raised for transport, clothing, and meat. Though apparently docile, hammelhorns were unpredictable by nature and could be dangerous if angered. Rubbing a hammelhorn the wrong way caused its fur to bristle, a quality that existed even in coats made from their skin. Twig recieved a hammelhornskin waistcoat from a tribe of slaughterers when he was thirteen years old, which helped him escape the grusome fate of being eaten by a bloodoak. Hammelhorn bladders were also sometimes used to make Trockbladder balls.

Their prefered habitat tended to be grassy plains, and they were numerous on the Silver Pastures. Many were transported to Undertown, and their strength was utilized to pull wagon loads - with the arrival of Stone-Sickness, hammelhorns became an important means of transport to and from the Deepwoods.