Little Mouser (character)
From the Super Mario Wiki
Little Mouser is a character in Paper Mario. An inhabitant of Dry Dry Desert, Little Mouser is a Nomadimouse and the owner Little Mouser's Shop. He is also a member of Moustafa's unnamed organization.
Little Mouser is first seen when Mario first enters Dry Dry Outpost; Little Mouser can be seen running quickly from his shop, which he temporarily closes, to Sheek's House for some unrevealed reason. When Mario approaches Sheek's House, Little Mouser will rush back to his shop, which Mario can then purchase items from.
In order to gain a meeting with Moustafa, Mario would need to go to Little Mouser's Shop and buy a Dried Shroom and a Dusty Hammer in that order; upon seeing Mario do this, Little Mouser, believing Mario to also be a member of Moustafa's group, will tell him that to find Moustafa, he would need to go to the highest point in Dry Dry Outpost.
Later, Mario can deliver a letter to Little Mouser from Miss T. upon getting this letter, Little Mouser will reveal it is an order for various beauty products and that Miss T. is one of his best customers. Little Mouser, after reading his letter, will give Mario one of his own, to be delivered to Franky in Boo's Mansion. Additionally, one of the favors Mario can perform for Koopa Koot involves obtaining a Red Vase from Little Mouser, who will give Mario the artifact if he purchases a Dusty Hammer, some Dried Pasta, another Dusty Hammer and a Dried Shroom, in that order, from his shop.