The remarkable "prehistoric" appearance of these mammals is largely due to the prominent upwards incurving canine tusks of the males, which actually pierce the flesh in the snout. If a babirusa does not grind its tusks (achievable through regular activity), they can eventually keep growing so as to penetrate the animal's own skull.
Babirusa are notable for the long upper canines in the males. The upper canines of male babirusa emerge vertically from the alveolar process, penetrating though the skin and curving backward over the front of the face and towards the forehead. The lower canines also grow upwards. The canines of the female are either reduced or absent. The structure of the male’s canines vary by species. In the golden babirusa, the upper canines are short and slender with the alveolar rotated forward to allow the lower canines to cross the lateral view. The Togian babirusa also has the same characteristics and the upper canines always converge. The North Sulawesi babirusa has long and thick upper canines with a vertically implanted alveolar. This caused the upper canines to emerge vertically and not cross with the lower canines. Babirusa also vary by species in other characteristics. The golden babirusa has a long, thick pelage that is white, creamy gold, black or gold overall and black at the rump.