Darth Vader is a tattooed 43-year-old former Marine who owns a gym and is raising funds online for a bone marrow transplant.
The Democrat and Chronicle of Rochester reports that a western New York man legally changed his name last year to match the villain in the "Star Wars" films.
The former Eric Welch, of Canandaigua, says he grew up in foster homes and didn't have strong family ties to his name.
The "Star Wars" fan says he chose Darth Vader for his new name because the character carries an aura of leadership and toughness.
He tests his own toughness by competing in half-marathons and endurance events. He was diagnosed with leukemia in 2002.
A spokeswoman for the Department of Motor Vehicles confirms that Darth Vader is his legal name.