The Skull hermits are a race of sentient creatures that make their homes inside the skulls of dead giants. Although a hermit has never been seen outside of it's shell, speculation of their shape and origin is that of failed splicing experiments of Gastropod, Crustacean, and mammalian DNA. The horns on the skull-shell are actually smaller snails living in a symbiotic relationship, They feed off the remains of a Skull hermit's latest hunt, and in return add another layer of protection to the hermits shell. We can see this one is outgrowing it's shell as the foot of the hermit swings about like a tongue underneath.

Here is the B&W, as usual: