Dethklok is the fictional band in the AdultSwim cartoon show "Metalocalypse". It's written and produced by Brendon Small who also writes and performs a significant portion of the music.
Dethklok is both a virtual band featured in the Adult Swim animated program Metalocalypse and a real band created to perform the band's melodic death metal music in live shows. Both bands were created by Brendon Small and Tommy Blacha. The music heard on Metalocalypse is performed by Brendon Small, with others needed for live concerts and albums.
The first official Dethklok album was released on September 25, 2007, entitled The Dethalbum. The album debuted at number 21 on Billboard Magazine's Top 200 list. The band released Dethalbum II on September 29, 2009, and toured with Mastodon, High on Fire and Converge. The band's third album, Dethalbum III, was released on October 16, 2012. The soundtrack to the special episode, Metalocalypse: The Doomstar Requiem was released on October 29, 2013.