The Legend of Zelda: Ocarina of Time 3D Unlockables

Biggoron Sword Trading Quest
The Biggoron Sword is an adult only two handed sword that causes double the damage of the master sword and has longer reach. The drawback is that you can't use your shield at the same time. Unlike the Giant's Knife, this sword will never break.

To claim this sword you need to complete this trading quest. You need to work through each item in order. Note that for timed items you are not allowed to use warping songs or you will fail immediately.
Trade ItemWhere to obtain it
Pocket EggTalk to the Cucco Lady in Kakariko Village near the graveyard entrance.
Pocket CuccoLet time pass until morning comes around while you have the egg (sun song helps).
Cojiro (Blue Cucco)Use the pocket cucco to wake Talon (sleeping in the left house near the village entrance from Hyrule Field), then give it back to the Cucco lady.
Odd MushroomGo to the lost woods. Once you enter, take a left and walk up to the wierd guy with the liberty spikes and hand him the Cucco.
Odd PotionRush over to the old potion lady in Kakariko Village - she lives in the only house with a purple roof. As a shortcut you can go to the new Potion Shop. If you go to the dark space in the back, you end up in the area with stairs to the Old Potion shop. You have a time limit of 3 minutes. Note this this part will also make blue potions buyable from her for 100 rupees.
Poacher's SawGo back to where you talked to the weird guy in the Lost Woods, and he won't be there anymore. Instead there will be a blonde girl. Give her the potion and she will give you this.
Broken Biggoron's SwordGo to Gerudo valley. Give the head carpenter the saw.
PrescriptionTake the broken sword up to the giant goron on top of death mountain.
Eyeball FrogGive the prescription to King Zora in Zora's Domain royal chamber (you will need to unfreeze him with blue fire first).
EyedropsGo to Lake Hylia laboratory (the building you see after entering from Hyrule Field) and give the frog to the guy inside. You have 3 minutes to do this.
Claim CheckTake the eyedrops to the giant goron on top of Death Mountain. You have 4 minutes to do this.
Biggoron Sword (Usable)Allow 3 days to pass (play the sun song 6 times). Give the claim check to the giant goron.