Thomas, also known as the Thin Man or Skinny Man, is a character featured in Oracle of Ages.
In the house located at the lower, central portion of Symmetry Village in the Past is a guy known only as the Thin Man. He is so tall and thin that he can't help but to sway from side-to-side, something that he wishes he could change. His only problem is that he has just one dumbbell to work out with, which he says goes against his policy to only work out one arm at a time.
As part of the Trading Sequence, Link will obtain the Dumbbell from Mamamu Yan in exchange for the Doggie Mask. Link can choose to give the Thin Man the Dumbbell so that he can finally work out both arms. In exchange, the Thin Man will give Link the Cheesy Mustache.
Thomas giving Link the Cheesy Mustache