Disclaimer: Harry Potter belongs to JK Rowling.
It was my last year at Hogwarts school of Witchcraft and Wizardry and I had a row with that narrow-minded boy, Draco Malfoy. He usually made fun of mud-blood witches, like me, but that day, I had my revenge.
I took my magic wand and took into account to change him in a little rat, but I changed my mind in the last moment and finally decided not to lose my opportunity of obtain my wizardry degree, so I only gave him a confundus spell, then he thought he was a little white rat for ten minutes and he started to eat the garden grass. When he made sense of the things he was eating, his face paled and all of my Gryffindor`s partners laughed at his disgrace.