Once a long time ago, in the ages of mythical creatures, there was an arctic fox named Trixie. Trixie liked two colors: silver-white and treebark-brown. Back then, arctic foxes were black. Trixie thought black was too plain, so one day, she had an idea. She would jump in a paint bucket to change her color. But, which color would she use?
Trixie was thinking about this when she bumped into a unicorn. Trixie quickly said, "Sorry!" Then she remembered that the unicorn could help her! "Great, mighty unicorn; may I ask for a favor?"
"I do not reward creatures who bump into me!" exclaimed the unicorn.
"Please; I'll do anything!" Trixie pleaded.
"Okay," said the unicorn. "If you get me some mushrooms, I'll do what you want me to do."
Nine hours later, Tixie returned with some mushrooms. "Okay, what was it you wanted me to do?" the unicorn asked as she took the mushrooms.
"I want you to make it so that half of the year I'm treebark-brown and the other half I'm silver-white," Trixie explained.
"Okay, I can do that," the unicorn said. Then, she mumbled a spell. A second later Trixie was brown.
"Thank you!" she said.
"You're welcome!" said the unicorn and she vanished.
Ever since then, arctic foxes have been silver-white for half of the year and treebark-brown for the other half of the year.