Aveil

Aveil is the leader of the Gerudo tribe of Termina in Majora's Mask. She is the Terminan counterpart of the Gerudo in charge of the Gerudo's Fortress in Ocarina of Time.

Ocarina of Time
Though Aveil does not appear in Ocarina of Time, her identical Hyrulean counterpart, who remains unnamed throughout the game, does. While Nabooru is away in the Spirit Temple, she leaves this Gerudo in charge of the Gerudo's Fortress. After Link frees all the carpenters, Nabooru's second-in-command appears to compliment him on accomplishing such a task and reward him with the Gerudo's Membership Card, which allows Link to walk about freely in the Gerudo Fortress and access the Haunted Wasteland.

Majora's Mask
In Majora's Mask, Aveil is the leader of the Gerudo Pirates. She has a room deep inside the Pirates' Fortress that is filled with all kinds of treasures and luxuries that the pirates have stolen, including a Zora Egg and the Hookshot.

After infiltrating the Pirates' Fortress, Link overheard Aveil speaking about the Zora Eggs which they had stolen from Lulu; where they are and why they stole them in the first place. Apparently, the Skull Kid had told them that the eggs were key elements in obtaining a treasure that should be lying in Great Bay Temple. Aveil wants the eggs for the treasure, but also fears the harm done to their reputation if people would find out that they couldn't hold on to their loot. Eventually, Link shot a beehive hanging on the ceiling of her room, which caused the bees to come out and chase away Aveil and the other pirates. She is not seen anymore after that.

Trivia

 * In Ocarina of Time, the clothing and lipstick of the Gerudo in charge of the Fortress changes to match the color of Link's tunic; a feature which, for unknown reasons, was removed from the GameCube and 3DS versions, where her clothes are red regardless of Link's outfit.
 * As with a couple of other names in Majora's Mask, the name similarity between a Terminan and Hyrulean went lost in romanization. In direct romanji, the name Abēru clearly is supposed to remind of Nabōru.