The beast's scientific designation is Regaliceratops peterhewsi, but paleontologists have bestowed the nickname "Hellboy" on a newly discovered horned dinosaur that lived some 70 million years ago, Cell Press Current Biology reported.
Hellboy's most remarkable feature, along with its sharp facial horns, is a shield-like appendage that crowns its head.
The skull of the Regaliceratops, closely related to the Triceratops, was found 10 years ago by Peter Hews among fossil bones sticking out of the ground on a ridge overlooking the Oldman River in Alberta, Canada.
"The specimen comes from a geographic region of Alberta where we have not found horned dinosaurs before, so from the onset we knew it was important," study co-author Caleb Brown, of the Royal Tyrrell Museum of Paleontology, said in a statement.
"However, it was not until the specimen was being slowly prepared from the rocks in the laboratory that the full anatomy was uncovered, and the bizarre suite of characters revealed," he said.
"Once it was prepared it was obviously a new species, and an unexpected one at that. Many horned-dinosaur researchers who visited the museum did a double take when they first saw it in the laboratory," Brown said.
What makes the dinosaur striking is its size, its horns and the shield-like structure that Brown described as a halo of large pentagonal plates radiating outward with a central beak.
The specimen is important because of the implications it may have for understanding the evolution of ornamental horns in dinosaurs.
Until now, scientists have divided horned into two groups: Chasmosaurines, with a small horn over the nose, larger horns over the eyes and a long frill; and Centrosaurines, characterized by a large horn over the nose, small horns over the eyes, and a short frill.
"This new species is a Chasmosaurine, but it has ornamentation more similar to Centrosaurines," Brown said. "It also comes from a time period following the extinction of the Centrosaurines.
Hellboy's anatomy and age strongly suggest that the two groups of horned dinosaurs independently evolved similar features, a process known as convergent evolution.