Long ago, in a forest, lived a young girl who served as an apprentice of the goddess of weaving. She was cared for and well-provided for by her supernatural benefactor.
One day, the goddess instructed her to prepare a dress by cleaning some cotton, beating it, spinning it, weaving it into cloth, cutting it, and finally sewing it.
Unfortunately, the young girl was quite lazy and found the dress-making process too tedious. So she took the leather cloth (used to beat the cotton on), a wore it thinking it would make a much longer-lasting dress.
Enraged, the goddess punished the young girl by making the leather stick to her skin, and by attaching the beating stick to her body.
So when you see a monkey with leather skin and a long tail, remember that lazy girl who once didn’t have to struggle in the forest to keep herself alive.