A film based on Magneto, a nemesis of the X-Men, is in the works for 20th Century Fox, Variety reports. Writer Sheldon Turner, who has done work on recent remakes of "The Longest Yard," "The Texas Chainsaw Massacre," and the "Amityville Horror," is working on a treatment. Magneto has been played by Ian McKellen in the two "X-Men" films, but because the spin-off script will focus on Magneto’s formative years, it may not include the British actor.