Oldman is an English actor known for playing eccentric characters and for his ability to master accents. He first appeared on screen in the 1982 film Remembrance and has since played a variety of characters including Dracula, Beethoven, and Sex Pistols bassist Sid Vicious. In 1997, he wrote, directed, and produced Nil By Mouth, an award-winning film reportedly based on his life. Recently, he has received acclaim for his portrayal of which character in the Harry Potter film series? Discuss