The Biggoron's Sword is the third and final sword that Link recieves in Ocarina of Time. Wielding this sword has it's pros and cons. It takes two hands to wield, so you cannot use your shield while you have Biggron's Sword, but it dishes out twice as much damage as the Master Sword. To get Biggoron's Sword you have to go through a fairly large sidequest with multiple stages, most of which are timed.
Note: Before attempting to get Biggoron's Sword, make sure you have already gotten Epona and have planted a seed in the patch next to Dodongo's Cave. If you do not do these two things, it is likely that you will not be able to complete each step fast enough.
 Step 1
- Speak to the Cucco Lady in Kakariko Village, she will give you an egg. Wait one night to let the egg hatch.
 Step 2
- With the hatched cucco, go into the inn in Kakariko Village. You should find Talon asleep on a bed. Show him the cucco and he will wake up. Return the cucco to Cucco Lady to reviece the Blue cucco.
 Step 3
- With the blue cucco, go to the lost woods, take the first left and you'll see an old man, use the cucco to wake him up and he'll give you an odd mushroom and tell you to bring it to the "old hag in the potion shop".
 Step 4
- If you take too long the mushroom will spoil so you will be timed for this step, ride Epona to Kakariko VIllage as fast as you can and then go through the newly built potion shop to get to the one the old man was talking about. Show the mushroom to the old lady and she'll give you a potion in return.
 Step 5
- The Potion will also spoil if you take too long so you are once again timed, go back to where the old man was in the Lost Woods. This time there will be a kokori girl. Give her the potion and she'll give you the poacher's saw.
 Step 6
- Go to Gerudo Valley and give the poacher's saw to the carpenter. In return he'll give you a broken sword.
 Step 7
- Go to the top of Death Mountain and talk to Biggoron. Unfortunately he can't see very well so you need to get him eyedrops so he can make you the sword. He will ask you to get eye drops, and give you the eyedrop prescription.
 Step 8
- Go to Zora's Domain and give King Zora the eyedrops prescription, in return he will give you an eyeball frog.
 Step 9
- Take the eyeball frog to the scientist at Lake Hylia, but remember, there is a time limit of three minutes. The scientist will then give you the eyedrops.
 Step 10
- This is the last step and also has a time limit, this time the time limit is four minutes. You need to get all the way to the top of Death Mountain. Race over with Epona and give the eyedrops to Biggoron. Wait three days and nights (you can use the Sun's Song) and your sword will be ready.