This is my opus:
From what I've read, this is an instrumental inspired by H. P. Lovecraft's Call of Cthulhu. Any mortal man is advised never to speak Cthulhu's name aloud, for fear of calling the beast. This may be why Metallica chose to change the spelling of it's name, as well as speak no words in the song.
Go ahead, I dare you. Speak it's name three times in front of a mirror in a darkened room. Scared? Mwah ha ha ha!!
Thanks for such a cool pattern, Rhoda!