"Hamburger time" is a euphemism used by the band Dethklok for anything to do with actual death.
It originated in "Dethhealth", during a meeting with Offdensen to discuss a recent concert where the band was nearly crushed by the decapitated head of the Sphinx of Giza.
Nathan expresses his displeasure at the number of times Offdensen uses terms like "die" and "dying", demanding he "use a different word, something like...something that's good". Murderface immediately suggests "hamburger time" as a more upbeat-sounding term, which is agreed upon and adopted by the rest of the band.
"Hamburger Time" is also the fan-given title for the song at the end of the episode. Not considered a Dethklok song, it appears in a bizarre dream-sequence imagined by Toki, when he becomes overwrought and faints after discovering his cat has died.
All five members of Dethklok do appear in the dream-sequence, however. Each one sings about their subplot in the episode, and how it resolved itself — with the exception of Skwisgaar, who did not have his own subplot.
- Toki says a wistful goodbye to his dead cat.
- Pickles gloats that he is not actually dying and can resume abusing drugs and liquor.
- Nathan states that he has befriended his dentist and believes he is no longer suicidal.
- Murderface gleefully brags "I jacked off on a doctors face!" This had happened during a routine hernia-check, and caused Murderface considerable anxiety over his sexuality (until he realized the doctor intentionally gave him a hand-job, meaning he is gay and Murderface is not.)