The Desert Trader is a merchant that players can only access in the Calico Desert. He has a stall along the road the bus travels along, and he wears a snazzy-looking turban. The Desert Trader has a very interesting inventory, including some unique items that you cannot acquire elsewhere, including your snazzy turban. However, he doesn't accept the standard currency for his goods. Instead, the player will have to collect the items that he wants, and in return, he will trade you for the item you want. The good news is that most of the items that he wants can be found in the Skull Cavern, so you need only spelunk for a while, and you should be able to gather what you need.