Weevil

Best answer as chosen by Asker / Ratings
You need to clear out the cursed skulltula house on the beach, and you have to do it before the 3rd day. You'll need the Hookshot for this mini-dungeon (obtained at the Pirates' Fortress).
Look for the skulltulas inside pots (roll attack into them), the cracks between the walls and the ceiling, the chandelier (use Goron Ground Pound on table), behind paintings and behind cobwebs.

When you destroy all the skulltulas, head back to the entrance and a guy will be there. He is the one who gives you the huge wallet.

You'll need to talk to the Stalchilds with the Captain's Hat (obtained from the graveyard near Ikana Canyon, after defeating the huge Stalchild) to get the combination to get into the fireplace, where a Piece of Heart is.