A normal beard. Except that it sprouts from a man's (usually) scrotum--his ballsack. They can be a variety of colors, and can come in many different shapes and sizes. Some are curlier than others, and some are thicker than others. It all really depends on the person. And legend has it--scrotum beards are actually what allows people who live in cold climates not to get scrotum frostbite.

Do you have a scrotum beard?

When you eat dirt for the first time and leave your family to build a shack in the woods