nearly twice as tall as horses , they stood on slender but wiry-looking legs with bulging knees ; they had thickly-built bodies with a strikingly big hump in the middle of the back , and their neck , long and curvy and adorned with a beard-like tuft of hair , ended in a head whose shape and facial mobility undermined their overall fearsomeness : long and flat , with heavily-hooded , kindly-stupid eyes and a comical set of lips which never ceased to move , as if the beasts were mindlessly munching on stones .