Hide armor is a common item of equipment in most Fantasy Role-Playing Games. Although it saw little use in the real world aside from prehistoric man.
This armor is constructed from the thick skin of a large animal, such as an elephant. It is very heavy and inflexible, making it unpopular among any cultures that are capable of producing better forms of protection. But among barbarians and humanoids, hide armor is king.
Hide armor is often worn untanned, and will have a very distinctive smell. Humanoids commonly adorn their armor with body parts from slain foes, adding to the already pungent odor. Different tribes often adopt armor made from specific animals, as they believe that the animal skins will imbue the wearer with the animal's power.
No armor is as unsanitary as untanned hide armor, which is often the bearer of many forms of disease. Tanning the armor will solve this problem, but most cultures that are smart enough to do that, are smart enough to make better armor in the first place.
Some role-playing games even have magical hide armor that will imbue the wearer with animal-like powers and magical hide armor is the route to becoming a werewolf in some versions of the legend.