Merlow is a young shaman boy found in Paper Mario. Merlow lives in Shooting Star Summit with his older sister, Merluvlee. Merlow is a collector of Star Pieces, and is willing to trade rare badges in order to add to his Star Piece collection. Some badges you can only obtain by trading with Merlow, but other badges he has can be found in other places. Either way, in order to collect every badge, Mario must trade Star Pieces with Merlow.
In Paper Mario: The Thousand-Year Door, Dazzle replaces Merlow as the Star Piece trader.