Madam Pomfrey is a minor character in the whole Harry Potter series.
Full name: Madam Poppy Pomfrey
Madam Pomfrey is the Hogwarts school nurse who runs the Hospital Wing.
She is strict with all those who enter her domain but always does her upmost to aid in the students expedient recovery. With a wave of her wand or the right potion Madam Pomfrey can cure or fix almost anything that ails her patients. Enlarged teath, colds, broken bones, and a nose that has been hexed off are but a few of the things that have been treated in the course of the series. She is also rather prudent in the fact that she is know not to ask too many questions that will just make things more complicated. A good exampel of this is when Ron Weasley had to visit her to get a dragon bite, from Hagrid's Norweigian Ridgeback, treated.
Madam Pomfrey has been at Hogwarts for many years. This is know because Sirius Black (Harry's godfather) mentioned that when he was at school there she treated him too.