Merlow

Merlow is a Shaman-like character seen only in Paper Mario. He is Merluvlee's younger brother (and therefore also Merlee's younger brother, as Merlee and Merluvlee were depicted as twins in Paper Mario), and he lives with Merluvlee in a large house on Shooting Star Summit. He collects Star Pieces and will trade rare Badges for them. Merlow seems to be very young, as his cloak seems to be too large for him and Goombario mentions wanting to play with him some day, indicating that the two are of similar ages. Another indicator of Merlow's youth is his natural blond hair, as opposed to his grandfather Merlon's white hair.

In Paper Mario: The Thousand-Year Door, Dazzle fills the same role as Merlow.

Goombario's Tattle
"He's Merlow. He's about the same age as I am. I wanna play with him when we finish our adventure. I guess he trades Star Pieces for Badges. Merluvlee, who's downstairs, is his sister. He's so lucky!"

Trivia

 * Merlow's name is a portmanteau of "Merlon" (or perhaps Merlin) and the word "low", emphasizing on his shortness and youth.