How Do You Make a Unicorn?

"You just twisted science into science fiction, Jon! What will that do to the world?" asked Karyn. "Genetic engineering isn't science fiction, Karyn. Remember Dolly the sheep?" "Oh yeah, I forgot. But how would someone create unicorns. They're mythical beings, aren't they?" "I'm not the scientist, Karyn. Anyway, what do you want to do now?" "I thought we could go riding on our new unicorns," Karyn said. "Great idea."