Flat

Flat is a recurring character in the Legend of Zelda series. One half of the Composer Brothers, Flat is the younger brother of Sharp. In life, Flat and Sharp were court composers to the Royal Family of Hyrule. After they died, they linger on in the mortal plane as Poes.

Flat's appearance, being slightly thinner than his brother and wearing green robes, is an obvious reference to Luigi, the brother of Mario, from the famous Super Mario series of games.

The Legend of Zelda: Ocarina of Time
When Link examines one of the gravestones in Kakariko Graveyard, Flat appears and attacks him. Link defeats Flat's ghost, who surrenders and tells him about the history of himself and his brother and how they came to write the "Sun's Song", a mysterious song that holds the power to control time. After Link has entered the Royal Family's Tomb and found the notes to the song etched on the wall, Flat explains to Link about the song.

The Legend of Zelda: Majora's Mask
Wearing the Captain's Hat, Link orders some Stalchilds to open a grave in Ikana Graveyard on the First Day. Link enters the passage that appears and finds himself inside a huge cave complex beneath the graveyard. With the help of the Lens of Truth, he sees through the deceptive surfaces of the area and finds a huge room with a stage and curtain. After defeating an Iron Knuckle, the curtain is raised, revealing a gravestone with notes inscribed on them.

From out of nowhere, Flat's voice sounds. The apparation appears and explains to Link that he and his brother were once great composers in life, but his brother turned to evil and betrayed him. He asks Link to learn the song inscribed on the stone, the "Song of Storms", a composition saturated with the grief and anger he holds towards Flat and play it for his brother. He then disappears. Link plays the song for the ghost of Flat, who is freed from the grip of evil.