The crossword solution for the term 'Potter Antagonist' is Snape, a five-letter word. Snape is a character from the Harry Potter series of books and films, and is one of the main antagonists of the story. He is a professor at Hogwarts School of Witchcraft and Wizardry and is known for his cold and calculating demeanor. He is also a former Death Eater, a group of dark wizards loyal to Lord Voldemort.