Tiki Sam is shopkeeper of the Tiki Hut. Mickey can buy things from him
Tiki Sam's shop
to help him with his adventure. He is shown to be a cheapskate, this trait being highlighted more in the sequel.
One of the quests that Sam gives Mickey requires him to locate three Tiki Masks and return them to him in exchange for the Ship Wheel. If all three masks are brought to him, he gives Mickey the Wheel along with a discount on everything in his store. However, if Mickey does the "same mask twice" trick and brings the other masks so that Sam gets four masks, he'll realize he's been tricked and gives him the wheel out of frustration. And as expected, no discount. Sam will also be rude to Mickey every time he visits the shop.
In the sequel, Mickey can buy things like the Anvil Sketch and the Giant Pearl for a mission. The giant pearl will be stolen if Mickey and Oswald go in the back end of the store and pick it up.