Beautiful, excellent color patterns and shading. The frill is amazing, that's definitely the hardest part of this animal to get right.
Suggestion: the portion of the snout between the beak and the nasal horn needs to be longer. It's fairly long in Pentaceratops, in fact most of the snout is in fron of the nasal horn - the horn itself is bunched up pretty close to the orbital horns (in such a position so as to be almost useless for attack or defense despite its large size for a chasmosaurine nasal horn).
Suggestion: the portion of the snout between the beak and the nasal horn needs to be longer. It's fairly long in Pentaceratops, in fact most of the snout is in fron of the nasal horn - the horn itself is bunched up pretty close to the orbital horns (in such a position so as to be almost useless for attack or defense despite its large size for a chasmosaurine nasal horn).