You may not know him, but Ralph Bakshi is perhaps well-known for starting the trend that we now called Adult Animation.
Born in Israel but raise in New York, Ralph works his way up in the animation industry, working in Terrytoons and the 1960's Spider-Man. By the time the 70's arrived, Bakshi made a name in the big screen, starting off with the X-rated "Fritz the Cat", which earned a big hit by critics and audiences. From there, he continues to create more adult theme in each of his works, including Coonskin and American Pop.
Even though he hasn't made any films since "Cool World", the 21st century may prove to be his big comeback.