Polyjuice Predicament

A student of Hogwarts ends up becoming a girl for life when the potion goes wrong

Spell-Stuck Situation

When a student ends up forced to wear girls clothes when a spell goes array

Making of a mermaid

When a student makes a deal with a mermaid, ends up getting more than he asked for

Woman Werewolf

When a boy is bitten by a werewolf is given a potion to remain calm, something happens when the full moon fades.

Growing a girl

When a couple of curses hits a student in a chest during a duel, he wakes up in hospital with permanent side effects.