Professor Trelawney is one of the most fun characters in the film series, always there to bring some levity when the moment requires it. She taught Divination to Harry and his friends, and they rather cruelly believed her to be a fraud, which wasn't always the case.
Behind the character was the legendary Emma Thompson. An elegant, sophisticated British rose, Thompson has done it all in the world of entertainment. As skilled as a comedian as she is an actor, she's also shown her ability as a screenwriter and author, generally regarded as being one of the greatest female performers of her generation. She's also very highly outspoken on liberal political issues, being a keen supporter of Greenpeace and AIDS awareness campaigns, as well as a strong critic of organized religion. She's also received the impressive sounding title of Dame Commander of the Order of the British Empire.