Joss Whedon.

Joseph Hill Whedon (born June 23, 1964), known professionally as Joss Whedon, is an American screenwriter, director, producer, comic book writer and composer who wrote the 1997 film Alien Resurrection. He is perhaps most famous as the director/writer of The Avengers and creator of Buffy the Vampire Slayer.

Whedon also wrote the screenplay for the 2000 film Titan A.E., featuring Ron Perlman.