Note:There are some special items that you can give to people as a child, but the true item trading game does not begin until you are an adult.
As a child, you can use the following special items:
Egg - Malon should give you this egg when you are a child. This occurs when you are seeking for a way into Hyrule Castle. Malon is standing in front of the vines which you will have to climb. If you speak to her, she will give you the egg. Set the egg to one of your "C" buttons and wait for about 24 hours. A chicken should hatch from the egg. "Use" this chicken on Talon (who is sleeping) to wake him up.
Zelda's Letter - You will receive this item from Zelda herself. After you speak to her in the castle courtyard, she will give you this letter to help you in your quest. You must show this letter to the gatekeeper in Kakariko Village.
I believe that these are all the items that you will be able to trade (with the exception of the masks, which there is more information about in the "Masks" summary) while you are a child. Like I said before, the real game begins when you are an adult.
Here are the items that you will have to trade as and adult:
Egg/Chicken - Speak to the woman in Kakariko Village who is allergic to the chickens (remember how you helped her find them all as a kid?). She will either give you an egg or a chicken. If it is an egg, just play the Sun Song a few times and it will hatch. You will find Talon sleeping again in a house (this time in Kakariko Village). You will have to use this chicken on him to wake him up. When you have done this, bring the chicken back to the allergic girl again. She will give you the next item�
Blue Chicken - She will give you a small, blue chicken, whom she says is very unhappy. It will have to wake up somebody who is extremely sleepy to feel good again. Go to Kokiri Forest and enter the Lost Woods. Make your first left and you will find a sleeping black kid laying up against a tree stump. Wake the kid up with the blue chicken. The kid will then give you the next item�
Mushroom - You will have to take this mushroom back to the "old hag" in Kakariko Village. I think that there might be a time limit to get it there before it spoils. It is very good if you have Epona at this point, for the horse will get you there much faster. Enter the potion shop in Kakariko Village and speak to the man behind the counter. He will tell you to walk in the little doorway just to the left of the counter. When you walk through there, you will find the entrance to the old woman's shop. Give her the mushroom and she will give you the next item�
Potion - Granny will give you the potion and tell you to bring it back to the black kid in the Lost Woods. Go back to the same place in the woods and you will find that the black kid is gone. There will be a Kokiri girl standing there instead. Speak to her and "use" the potion on her. She will give you the one item that the black kid left behind�
Poacher's Saw - That item is the poacher's saw. You MUST have Epona at this point, or else you cannot continue your item trading. You have to ride over to Gerudo Valley and spur Epona over the canyon that the bridge used to span. There will be a man standing outside of a tent. Use the saw on him and he will give you the next item�
Broken Sword - The next item is are the hilt-shards of a broken Giant's Knife. If you purchased this item for 200 rupees, then you were gypped, for it breaks almost immediately. You MUST have thawed out King Zora before you can continue the trading sequence. For more information on this, please see the "Ice Cavern" summary. Climb to the top of Death Mountain and you will meet a Biggoron there. Use the Broken Sword on him and he will make a request of you�
Prescription - The Biggoron will complain that his eyes are hurting. He will ask you to take his prescription to King Zora so that the king can make eye-drops for him. Bring this prescription to King Zora, and he will give you the next item�
Frogs - King Zora will give you frogs to take to the laboratory by Lake Hylia. You only have a limited time to get there, so take the quick way out of Zora's Domain - the swift river. Then get on your horse and move like the Devil himself is at your heels. When you make it to the laboratory, talk to the scientist and then "use" the frogs on him. After dashing his hopes that they are for dinner, he will give you the next item�
Eye-drops - The scientist will give you the eye-drops and instruct you to bring them to the Biggoron. This also has a limited time and is probably the most difficult to do. First you have to get back on your horse and haul ass to Kakariko Village. NOTE THIS: You cannot play any type of warping song or use any type of magic (such as Farore's Wind) or the eye-drops will be destroyed. This goes with all of the other items that have a time limit. Once in Kakariko, run up through the gate to Death Mountain. Make your way up the mountain quickly and try to dodge all of the falling rocks - every time one strikes you, you will be slowed and you will lose precious time. You must kill the spiders on the cliff before you climb. Climb to the top and run over to the Biggoron. Use the eye-drops on him. If you made it in time, congratulate yourself. The Biggoron will cure his eye infection and give you the next item�
Claim Check - The Biggoron will say that repairing the sword will take some time, and that you should come back in a few days. To hell with that! Stand there and play the Sun Song about 10 times, and then use the claim check on the Biggoron. He will give you the Biggoron Sword. It is much more powerful than the Master Sword and it is also much longer. The only drawback is that you need both hands to use it. The goal of the item trading game is to get the Biggoron Sword. You have now accomplished the task, and you are done with the items.
