These sturdy hogs are not among the world's most aesthetically pleasing animals. Their large, flat heads are covered with "warts," which are actually protective bumps. Warthogs also sport four sharp tusks. They are mostly bald, but they do have some sparse hair and a thicker mane on their backs. Warthogs are named for the four wart-like protrusions on their face. These are really skin-covered tusks.