The Doom Song was a song sung by GIR in the episode "The Nightmare Begins". It has a seemingly random tune, and its lyrics consist solely of the word "doom", sung over and over again. Upon hearing Zim speaking of "Raining doom upon the heads of our doomed enemies", GIR broke into song for a period of six months, stopping only when they finally reached Earth.
Popularity and other variations
The song has remained extremely popular with people, even after Invader Zim's cancellation. There have been shirts based on The Doom Song, and the most popular "Doom Song" video has reached 2.5 million views on YouTube as of June 2013, nearly 138% of the amount of views as the most popular Invader Zim episode video on YouTube.
There are many remakes of the song, including ones with only the audio from GIR's voice, but the song seen in the featured video is the most often used.
Other versions have also been featured on the popular PC game "Frets on Fire," a Finnish game made by Unreal Voodoo in 2006. In these versions, you play GIR's voice instead of guitar.