Throughout the game you will find Golden Skulltulas. These are the spiders which have bodies that look different from the regular Skulltulas. They are commonly found in dungeons, and outside at night time. You can hear them, so keep your ears out for their scratches, as they are often hidden. Once you kill them, they will present you with a token. Collect it. Once you collect enough tokens, take them back to the Skulltula House in Kakariko Village where you will be presented with rewards for your tokens. The rewards are as follows:

10 Gold Skulltula Tokens - Adult Wallet (200 rupees)
20 Gold Skulltula Tokens - Stone of Agony
30 Gold Skulltula Tokens - Giant Wallet (500 rupees)
40 Gold Skulltula Tokens - Bombchu
50 Gold Skulltula Tokens - Piece of Heart
100 Gold Skulltula Tokens - Rupee

For a location list of these Gold Skulltulas, please go here.