Don Gero's Mask

Don Gero's Mask is a frog-like mask found in Majora's Mask. It allows Link to communicate with frogs around Termina, to let them know that the Frog Choir is getting together to sing again. This can only be done after defeating Goht, when the snow disappears from Snowhead. The frogs are located in Clock Town's Laundry Pool, Woodfall Temple (after defeating Gekko), Mountain Village, Great Bay Temple (after defeating Gekko), and Southern Swamp near the Big Octorok. Getting all five frogs to the choir will earn you a Piece of Heart.

Obtaining the Mask
Before defeating Goht, go to the Goron Shrine and light the torches lining the wall. Equip the Bunny Hood, light the first torch, and use a Deku Stick to light the remaining torches. This will cause the hanging pots on the ceiling to begin spinning. Use the Goron Mask to roll off of a ramp on the top floor to collide with the pots until some sirloin rock falls from a pot. Bring this to the Mountain Village and give it to the Goron standing on a ledge who is hungry. He will thank you with the Don Gero's Mask.