Dr. Moira Kinross MacTaggert (sometimes spelled MacTaggart, McTaggart, or McTaggert) is a fictional character appearing in American comic books published by Marvel Comics, most commonly in association with the X-Men. She works as a geneticist and is an expert in mutant affairs. Olivia Williams played a minor role of Dr. Moira MacTaggert in X-Men: The Last Stand. Rose Byrne played the character in 2011's superhero film X-Men: First Class; Dr.