Link the Goron

Link-Goro (the name depends on your character's name in the game) is a Goron from Majora's Mask who comes to the Stock Pot Inn during the first day to pick up his room key. However, if you tell Anju, between 2-4 PM, that you have a reservation, she will give you Link-Goro's key. Since Link-Goro tends to add "goro" to the end of many of his words, he is informed that there is a reservation with a name similar to his, but he is not marked down for having a room. This results to Link-Goro spending the night outside of the inn.

As a side note, if you do obtain Link-Goro's key, there is a chest inside the room with a Silver Ruppee (100) inside of it.