Humans do not have hair on their tongues. Microvilli, which are present on the human tongue, sometimes are confused with hair. Mircovilli are microscopic membrane protrusions on the taste buds.
Occasionally, a person is afflicted with what is called "black, hairy tongue," according to WebMD. In such a situation, an individual appears to have coarse, black hair on the tongue. In fact, the individual suffers from excessive yeast growth in the mouth and on the tongue. The condition is harmless and is remedied by a more consistent, thorough course of proper oral hygiene. The condition can also make the tongue appear to be covered in brown, green or yellow colored hair.