Severus Snape is the Head of Slytherin House and the Potions Professor at Hogwarts. It is his job to look after all the students of Slytherin, make sure they are protected and safe, and learning to full potential. Because of the grief his students receive from the other Houses, he doesn’t like to take points from his house. Instead at the end of the day he will talk to the Acting Prince/Princess and the Knight of the offender's year and together decide a punishment that fits the crime. He also help maintain the order of ranks in the students and ensure they stand united against the rest of the school.