Kalm Traveler
From Final Fantasy Wiki
The Kalm Traveler is an non-player character in Final Fantasy VII. He can be found in the rightmost house in Kalm later on in the game and will accept trades with the player for three items that he is searching for. The items he is looking for are the Guide Book, the Earth Harp, and the Desert Rose. Trading them gives the player great prizes. After handing them in, the Traveler leaves the house to journey to parts unknown.
A funny thing is that if you have used an item cheat to get more than one Earth Harp the Old Man will continually give you more Master Materia unless you haven't picked it up already. If you don't pick up the materia it just bounces in the air instead of him throwing another one.
