The Great Fairy Mask
After turning back the clock 3 days for the first time and learning the Song of Healing, allowing you to return to your normal self, go to the laundry pool and rescue the stray fairy. Once again you should take her to North Clock Town to return the Great Fairy to her full form. She will give you the mask. When in each of the four dungeons, you will see stray fairies flying around. When wearing the mask, it will attract them to you, allowing you to bring them to the fairy fountain in each zone.
Mask of Scents
After saving the Deku Princess, the Butler in the Deku Shrine will offer you the chance to chase after him in a race. If you manage to keep up through the maze he will award you the Mask of Scents. It will make finding the mushrooms in the woods easier, which can be used to make potions.
See Anju & Kafei Quest. This mask will allow you to reach into the post boxes in Clock Town. You’ll find a heart piece and even rupees.
At 12:00 A.M. on the first night, be waiting in North Clock Town. An old lady will be walking by and Sakon the Thief will attempt to rob her. Fight him off and she will give you the Blast Mask. When worn it will allow you to explode, acting as a bomb. If your shield is not equipped it will do damage to you, but is helpful if you ever run out of bombs.
After obtaining the Blast Mask, go to the Curiosity Shop at 10:00 PM on the final night and the All-Night Mask will be for sale for 500 rupees. When worn, you will be able to stay awake during Anju’s grandmother’s stories. She tells two of them, and staying awake through each one will earn you two heart pieces.
Anju & Kafei Quest. Throughout the game you should have noticed circles of bushes with a bush in the center. When you attacked a bush, all of them would start shaking and moving away. When you wear the Keaton Mask however, a Keaton will appear and ask you questions. Answering them correctly will earn you prizes.
During the first or second night, go to the laundry pool and talk to Guru-Guru. He will speak to you a little and give you this mask for listening, since he no longer needs it. When wearing it, press the B button and you will march to a beat, attracting small animals around you to follow.
After you have the Bremen Mask, go to Romani Ranch and find the chicken coop. Use the Bremen Mask to line up all of the stray chicks. After doing this you will be given the Bunny Mask. This is very helpful because it allows you to run faster and jump further.
Buy a red potion and go to Ikana Canyon where there is a circle of stones. Using your Lens of Truth, you will see a soldier named Shiro. Give him the potion and it will heal him of the invisibility. In thanks, he will give you the Stone Mask. When worn it makes you invisible to those around you such as the Deku guards and those in the Pirate Fortress.
Circus Leader’s Mask
Once you have all for forms, go into the Milk Bar at night and play each part of the song on the stage (one part for each form). Gorman likes the song and will cry, and in thanks give you this mask. It can be used in obtaining the next mask. If worn, it will make the Gorman Brothers not attack the stage coach.
After you have saved the ranch from the alien invasion, arrive at the ranch at 6:00 PM on the second night and ride with Cremia to Clock Town. The Gorman Brothers will attack the stage coach, forcing you to defend it. If successful, she will give you the Romani Mask. This mask gives you access to the Milk Bar in Clock Town.
Don Gero Mask
Put the Goron child to sleep using the Goron’s Lullaby and then light all of the torches in the shrine. This will make the chandelier above start to spin. On the chandelier is 5 pots, using the Goron form, get enough speed to reach them and break each one until you find the one with the sirloin in it. Take the sirloin to the starving Goron outside of town and he will give you the Don Gero Mask.After you defeat Goht in the Snow Temple and the region will start to melt. There are 5 frogs throughout the game. One in Mountain Village by the lake, one in the Laundry Pool, one on a log in the Southern Swamp, one once you beat the Gekko in Woodfall Temple and one once you beat the Gekko in Great Bay Temple. Talk to each one wearing the mask and they will return to the lake. Once they are all there, return and talk to them and you will receive a piece of heart.
Enter the room on the right of the Mayor’s house and talk to Madame Aroma. If you agree to look for her son she will give you this mask. It is used a couple of times in the Kafei and Anju quest.
See Kafei and Anju quest. If worn, the people arguing inside of the Mayor’s office will calm down and he will award you with a piece of heart.
Exit the entrance of North Clock Town. There will be some mushroom a bit to the north east. Jump on them and there will be a pale man. Play for him the Song of Healing and he will give you the mask. It allows you to learn dance moves. In Clock Town, dance with the Rosa Sisters and they will give you a piece of heart.
Once you get Epona back, race the Gorman Brothers and they will give you this mask. It will make Garo’s appear in Ikana. After fighting them and winning they will give you hints or tips.
Mask of Truth
In the Southern Swamp, enter the Skulltula House and kill every Skulltula. You will be awarded the Mask of Truth which allows you to speak to animals and read the Gossip Stones.
Enter the cave in Ikana and play the Song of Storms, returning the river to its normal state and starting up the Music Box House. Once Pamela walks out of the house, sneak in and run downstairs to the armoire. Open it and her father will pop out. Quickly play the Song of Healing to return him to his normal state and receive the mask. When worm Gibdos will no longer attack you.
By Dampe’s house, play the Sonata of Awakening in front of the giant skeleton. He will awaken and chase you. If you manage to survive and defeat him he will allow you access to the chest behind him. Inside will be the Captain’s Hat. When on, the other skeletons will think you are him and allow you to command them.
Inside of the Stone Temple you will receive it just before the boss battle. Once you put it on, you will grow to an enormous size and be able to actually compete with Twinmold. It does use up your magic as you wear it however.