Manuel "Spain" Rodriguez, a prolific and seminal underground comix artist who produced work over five decades died November 28, 2012. He published one of the first underground comix series, Zodiac Mindwarp, and was probably most famous for his creations Trashman and Big Bitch. His social views showed through in his many counter-culture works, including his recent biography of revolutionary Che Guevara. A list of his various works can be found here, and his thoughts have also been well expressed in this interview about his Trashman series. Spain's artistic chops were well-honed from decades of drawing and creating his own works, which can be seen on his official website (note: NSFW).
Here is his obituary from The New York Times (also where I got the image above). This collection of thoughts, remembrances, and reflections from a variety of his colleagues, readers, and collaborators from Tim Hodler at The Comics Journal is an excellent celebration of the man. The Comics Reporter Tom Spurgeon also has amassed a number of links to various tributes.