Complex sentence: Shad comes across Space Cowboy, portrayed by George Peppard, of the planet Earth, essentially a spacegoing truck driver, who wears a Stetson hat, plays the harmonica, and has a fondness for old western films.
Split into simpler sentences: Shad comes across Space Cowboy, portrayed by George Peppard, from Earth. He is a spacegoing truck driver, who wears a Stetson hat, plays the harmonica and has a fondness for western films.