A stuffed monkey is an item that can be made by using seaweed on a monkey corpse. When given to Tamayu during the Tai Bwo Wannai Trio quest, he will skin the monkey and return the monkey skin and monkey bones, as well as the seaweed the player stuffed inside the monkey. The skin and seaweed are then used to create a sandwich as part of the quest.
Creating this item effectively saves one inventory space during the quest, given that both seaweed and monkey skin are required to create the sandwich.