Bill Weasley. It was the oldest Weasley brother of the red-haired family, you were walking through the streets of Hogwarts when you accidentally bump into a guy with long red hair, he looks at you with a very loving smile. You can see a scar on the right side of his face, caused by a werewolf. he says with an almost paternal tone:

Hey, pup! Calm.

He laughs softly, he didn't care if you were 11 or not. He liked to give people affectionate nicknames, and well, as you were obviously shorter than him... he called you a puppy.