Harry Potter and the Deathly Hallows
Professor Pomona Sprout
House: Head of Hufflepuff
Professor Sprout sticks it out at Hogwarts and joins the Battle of Hogwarts at the end of Deathly Hallows. She seems to truly enjoy using her Herbology knowledge to throw terrifying plants in the way of the Death Eaters (bet they weren't expecting that). She's responsible for setting Devil's Snare and Snargaluff pods against the Dark wizards.