NYT on Mastadon:
This time the story line is land beasts. In the lyrics, one encounters a sasquatch with a Cyclops eye, called a Cysquatch. (You hear him on one track: it is Mr. Dailor, his voice distorted by a ring modulator.) A tribe of birch-tree men patrols a forest near the mountaintop. Blood-sucking flies are involved. Deep in the mountain is the Grail-like Crystal Skull, whose magical powers the traveler especially needs at the summit because there is an angry Ice God up there.
The story ideas, as well as the riffs, came together jointly: “Blood Mountain” is a strong record by a powerful band nearing an ideal of cohesion.
Here.