“Welcome to 'Subcon', the land of dreams. We have been cursed by Wart and we are completely under his evil spell. We have been waiting for your arrival.”
The Subcons, also known as Subcon Fairies or the Muu people, are a peaceful fairy-folk that reside in and protect the land of dreams. In Super Mario Bros. 2, the dream world is known as Subcon, same as the fairies, which is a source of some confusion. It was initially postulated that the fairies were called "Subcon" in the credits by accident, however unlike other such mistakes (such as listing the Subcons in the "enemies" section), subsequent remakes of Super Mario Bros. 2 have not "corrected" this name.
 Yume Kōjō: Doki Doki Panic
The "Muu people" first appear in Yume Kōjō: Doki Doki Panic, the game that Super Mario Bros. 2 is based on. In this appearance, they are fictional characters in the Tale of the Dream World of Muu. The happy Muu people lived peaceful lives in strange land where the weather is decided by the "dream of the day": if everyone has a nice dream, then the weather is bright and sunny, but if everyone has a bad dream then the next day there will be storms. The Muu people invented the Dream Machine, so they could always have good dreams and good weather, but a mischievous monster named Mamu changed the machine to produce monsters. However, Mamu was weak to vegetables and hated them more than anything in the world. The Muu fought Mamu by hurling vegetables at him until he was buried. Mamu surrendered and peace was restored to the Dream World of Muu.
The story would have ended there had the "real life" twins Piki and Poki not squabbled over the storybook presented by Rūsa the monkey. They fought over the last page and accidentally tore out the book's ending. In a flash, Mamu sticks his hand through the pages of the storybook and kidnaps the two children, pulling them through the book and imprisoning them within a cage near the Muu people. This allowed Mamu to conquer the Dream World. Luckily, Rūsa alerted an Arabian family consisting of Papa, Mama, their son, Imajin, and their daughter, Lina. They hopped into the storybook to save the children, each progressing through the story at their own pace. In the end, after defeating the armies and their bosses, the four defeat the diabolical frog king and free the Muu people from Mamu's vase, thus restoring a happy ending. With the citizens rescued and the storyline fixed, the world they inhabit and the kidnapped children are rescued as well, and the six return to the Real World.
 Super Mario Bros. 2
In the Mario series adaptation of Yume Kōjō: Doki Doki Panic, the fairytale aspect was removed, and the land of Subcon was initially implied to exist only in Mario's subconscious, although the pseudo-sequel, BS Super Mario USA reveals that it is an actual dream world.
In Super Mario Bros. 2, the evil tyrant Wart mysteriously appears and takes over the land of Subcon and imprisons the Subcon fairies in a vase. For their last hope, the Subcons contact the great hero of the Mushroom Kingdom, Mario, in his sleep to ask for his help. They also give him a hint to beat Wart, which is his distaste for Vegetables. Mario, believing the message to be nothing more than a dream, dismisses it and later goes on a picnic to the park with Luigi, Toad, and Princess Toadstool. Mario then discovers a door in a cave leading to Subcon. Realizing that there may be some truth to his dream, Mario and his companions embark on a quest to save the fairies. After Wart is defeated, the fairies are released. They pick up Wart's battered body and carry it off-screen, leaving the fate of the frog king unknown, until BS Super Mario USA reveals that he and his crew escaped to another dream world. They eventually return, however the human king of Subcon uses the power of the Stars to summon Mario and the others once more, and Wart is defeated for good.
 General Information
Subcons first appeared in Super Mario Bros. 2, where they are inhabitants and loyal servants of the world's king (only seen in BS Super Mario USA). They are also known to protect the dream world and its kingdom. However, they are imprisoned by Wart and his crew, the 8 Bits, and one of them is even enslaved.
 Physical Appearance
All Subcons wear red or pink pajama-like clothes. They have black hair and are able to fly using their wings.
 Traits and Abilities
The Subcon fairies are capable of speech. They can contact others through their subconscious, as is done with Mario. Despite being capable of protecting the dream world and the kingdom, judging from physical appearance, the casual observer would regard them as physically weak. They are skilled in magical practices, as they can send people to alternate dimensions.