I just heard this song on Pandora:
Halfway through this song, I wondered if this was one of Jack Black's heavy-metal parodies. Nope. It seems to be submitted in earnest.
I guess Viking Metal is one of those things, like the Tea Party, soap operas, and something I was thinking of yesterday that I can't for the life of me remember, that is so over-the-top that it really can't be parodied.