Beginning in 1950, Freas provided the covers to hundreds of science fiction and fantasy magazines, including Weird Tales, Planet Stories, Astounding Science Fiction (and Analog), among many others. In the field of genre paperbacks, he created cover illustrations for DAW, Signet, Ballantine Books, Avon, all 58 Laser Books (which are now collectors' items), and over 90 covers for Ace books alone. He provided many covers for MAD Magazine, artwork for NASA's Skylab program, and in the Eighties, for numerous gaming publications. He also painted the cover to Queen's classic LP, News of the World, and was the first person to win ten Hugo Awards.
He passed away in 2005.