It's the song played at the end of the episode 19 season 1 called "Dethstars" where Dethklok is producing their own movie at the same title.
Ad blocker interference detected!
Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers
Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.