Ryo-ohki was a cheerful and curious cabbit. All year she'd watched as the Beard tried to manipulate Harry into going through that door on the third floor. Now the Grease had gone through, and come back dog-bit.
Inquiring cabbits want to know!
She turned intangible, and hopped through the door. A monstrous three-headed dog, barking and snarling, was upon her in a flash. My, intangibility was useful!
The dog was guarding a trapdoor. She slipped down through it, and landed in a soft patch of Devil's Claw. It tried to snare her, so she ate it. Ptui! Carrots were much better.
She wandered down the obvious trail, hopping through all sorts of interesting dangers, until she found herself standing in front of a mirror. She looked into it.
Carrots! Heaps and piles of carrots! And on top of the pile, Ken-ohki was smiling at her! She leaped into the mirror (oh, she loved that intangibility) and snuggled up to Ken-ohki. The two began to devour carrots.
After Hogwarts let out for the summer, Dumbledore shook his head sadly, and went to recover the Philosopher's Stone. The mirror of Erised was completely empty. SOMEBODY had gotten the stone!
Washuu looked askance at Ryo-ohki. "You're pregnant," she said. "Where on Earth did you find a boy cabbit?"
Ryo-ohki just smiled, twitched her nose, and turned another stone into a pile of carrots. She was eating for two, after all.