Disclaimer: I do not own the Legend of Zelda, any of the characters, or Nintendo. Although I am a Fierce Deity addict.
A Beast, a man, and a Mask: A History of the Origins of Majora, The Fierce Deity, and current day Termania.
Majora: The Beast and The Musician
In the land of Termania, there was an ancient beast that had been there since the beginning of time. It was forever in a torment that had been doomed on it since the day it was conjured. The torment caused him extreme pain, yet it couldn't die. He would remain in his vale until a human showed up.
Now, the naiveté of humans caused them to believe that if you asked the beast of something, he would grant your wish. Men, Women, and Children came before the powerful monstrosity and made their demands, but they were wasting their time. The beast would devour them. As time passed, the humans learned that the beast was dangerous, and left him alone.
Yet one day, a musician arrived in the area and heard the wild legend of the beast. Intrigued, he went and found it.
"I will end your torment, not with dance, but with music." He began to play a song. The beast, overjoyed, got up and danced. They sang and danced for three days, when the beast finally died of exhaustion. Amazed, the people worshiped the musician as a God for defeating the terrible beast. The musician went to the beasts corpse and carved out its armor plates. He then made a mask from the plates, the mask that he named Majora. He left his people one day, taking the mask with him. He traveled the world, and when he died, the village he died in inherited Majora. When the musician died, the mask, free of the musician's grasp, gained a power of its own...
Yey!
Note: The original idea of the Beast and the Musician is not mine. It comes from the Legend of Zelda Japanese manga.