The grass skirt is an item that you must purchase in Poptropica Shark Tooth Island. In order to speak with the Medicine Man at the top of the trees in the jungle, you need to look like a native islander and the grass skirt is the key to your disguise.
How to Get the Grass Skirt
To get the grass skirt, head to the right until you arrive in Booga Bay. Right near the entrance, you’ll see a man selling grass skirts at a booth. He’s wearing a white shirt with a blue tie and, of course, a grass skirt. Click on him and he’ll give you one.