Zak Penn (born March 23, 1968) is an American screenwriter. Penn wrote and directed Incident at Loch Ness and The Grand, wrote the script for The Incredible Hulk, co-wrote the scripts for X2, X-Men: The Last Stand, and the story for The Avengers. With Michael Karnow, Penn is the co-creator of the television series Alphas on the Syfy network.