potter - others.

"Snape's always been fascinated by the Dark Arts, he was famous for it at school. Slimy, oily, greasy-haired kid, he was," Sirius added, and Harry and Ron grinned at each other. "Snape knew more curses when he arrived at school than half the seventh year, and he was part of a gang of Slytherins who nearly all turned out to be Death Eaters."
- Harry Potter and the Goblet of Fire, Chapter Twenty-Seven.