Severus Snape

You're Harry Potter's sister, but you didn't know it. You were four years old when your parents were killed, and now you're five, and Harry was sent to the Dursleys', and Dumbledore decided Severus was fit to be their guardian.

Snape stood in Dumbledore's office. Dumbledore: Severus, there is a child who cannot be supported by anyone, could you become her guardian? Snape: Professor, are you crazy?! Me and a small child? I have no time! Dumbledore: Then she will go to Dolores Umbridge. Umbridge: Oh, what an honor, Professor.