Dethklok, Chimaira, Soilent Green

Dethklok started out as a joke and became the biggest death-metal band in the history of Billboard's album chart.

The show from which the band launched, Cartoon Network's Metalocalypse, premiered in 2006 with a simple but esoteric premise: What if the planet's most popular band was an extreme-metal group that actually lived in a world filled with the guts and gore that the genre's musicians (usually) only sing about? And what if it had fanatical legions of fans who lived—and literally died—for it? The show became an instant cult hit. The show even spawned a soundtrack, The Dethalbum, which sold more than 130,000 copies.

Creator Brendon Small recruited legendary California drummer Gene Hoglan to help make Dethklok's music, an oddly catchy mix of thrash, Cookie Monster growls and lovingly satirical lyrics. And now the live band is on the road, performing in the shadows as cartoon images unspool on a giant screen in front of the stage (a la the Gorillaz's live show).

"It pokes fun at metal from a fun way, because everybody involved in the show are fans of metal," says Hoglan. "I'd suggest that everybody come check it out, even if you don't like the [TV] show. The music is killer."