Joss Whedon, the creative force behind the “Buffy the Vampire Slayer” TV series and director of “The Avengers” and several other blockbuster superhero films, is having trouble proving who he is to New York City health officials.

Whedon, who was born Joseph Hill Whedon in Manhattan, alleges in a lawsuit filed Friday in Manhattan Supreme Court against the New York City Department of Health and Mental Hygiene that the agency refuses to give him a copy of his birth certificate because he does not have any government-issued documents bearing his birth name.