Zora Egg

From Zelda Wiki.org

One quest in Majora's Mask required Link to track down and return seven Zora Eggs. They were laid by Lulu and likely sired by Mikau, but were stolen by the Gerudo Pirates. Link had to infiltrate their hideout, making use of his new mask containing Mikau's soul, to get them back. After getting past the guards, he encountered four pirate minibosses, each guarding one egg. Link used empty bottles to easily transport the eggs. The final three were lost at sea and fell into an underwater cavern filled with Sea snakes, requiring Link to get rid of them all to retrieve the eggs. He then brought them to the Marine Research Laboratory, so they could hatch. Once all together in the tank, the eggs hatched and the baby Zoras taught Link a new song called the New Wave Bossa Nova.