It was done in an afternoon for a slot on local television back in '92 or '93 at about the height of the Norwegian Black Metal thingumy. It only actually features two proper Immortal members as far as I know: Abbath Doom Occulta and either his brother Demonaz Doom Occulta or Armagedda. The guy in the wizard hat and cape is I think just a mate of theirs, though it might by Jörn Tonsberg (Who played guitar on Immortals demos). It's essentially just a bit of a muck-around, never meant for wider release, and the band have named it as 'the most fucking stupid thing we ever did for money'.
I love it, myself. Immortals 'serious' videos are also quite silly, though undoubtedly some of the greatest black metal videos ever made, next to Satyricons 'Mother North', Burzums 'Dunkelheit' and the awesome, uncut, 9 minute video to 'One Rode to Asa Bay' by Bathory.