In the mid-1950s, Cobb was hired at age 18 at Disney Studios as an inbetweener. By 1957, he was a breakdown artist on Sleeping Beauty. He wafted in and out of odd jobs and was then drafted into the Army. In 1965, he began contributing political cartoons to the Los Angeles Free Press and soon became syndicated through the Underground Press Syndicate.
His comics were critically acclaimed but he made relatively little money off them. After a decade, he largely left the medium and started doing work in film and television. Which is where he's primarily known. Because he did design work on Star Wars: A New Hope, Alien, Conan the Barbarian, The Last Starfighter, Leviathan, The Abyss, Total Recall, Titan A.E. and Firefly. You may have heard of some of these, and maybe even seen one or two!
My dad had a couple books collecting Cobb's work from back in the day, as well as individual strips snipped from the newspapers. The books are long out of print, which probably is why he's not very well known in comics circles these days. But his work was timelessly poigiant (sadly) and deserves some wider recognition. Because despite only really working in the business for a decade, he made a lot of statements that were incredibly powerful. Powerful enough that they still resonate very strongly yet today.
Let me just leave you with a small sample of his work. If you can, I highly recommend you track those out of print collections down.