In December 1977, struggling Canadian comic book artist Dave Sim self-published the first issue of Cerebus the Aardvark, a Conan the Barbarian satire featuring a foul-tempered, sword-wielding creature trapped in a human world. Over the next 26 years, Sim, and later collaborator Gerhard, produced an epic 6,000-page graphic novel, the longest-running English language comic series by a single creative team. They revolutionized the comics...