After Quicksilver and the Scarlet Witch paved the way for mutants to join the ranks of the Avengers in 1965's issue 16, it took a few years for another member of the mutant community to sign up. But then, in 1976, Hank McCoy - better known as Beast - stepped up and, for five years, became one of the most-loved Avengers of all time. Why he won't be in the Avengers movies: The simple answer is "because Marvel don't own the film rights to the character." And that legal wrangling is a downright shame, because it's resulting in some daft retconning in the current Marvel comics (Quicksilver and the Scarlet Witch are now Inhumans, not mutants) and it stops the makers of these movies from adapting some truly great stories. For a mental idea of what Beast in an Avengers film would be like, just think of Kelsey Grammer's portrayal of the blue-furred, loquacious and hyper-intelligent scientist and imagine him pedantically correcting Tony Stark every five seconds. It would be a joy to behold but it doesn't look like it's going to happen any time soon.