If you're a dinosaur with the nickname "the chicken from hell", you'd better be able to back it up.
But a dinosaur called Anzu wyliei, which lived 66 million years ago and has been identified from fossils found in North and South Dakota, does just that.
It had a head shaped like a bird's, a toothless beak, an odd crest on its cranium, hands with big sharp claws and long legs for fast running.
Most startlingly, it was probably covered in feathers.
It is the largest North American example of a type of bird-like dinosaur identified from bones found in Asia about a century ago. But what would someone think if they encountered it?
University of Utah palaeontologist Emma Schachner, one of the researchers, said: "I don't know whether they would scream and run away, or just laugh, because it is an absurd-looking monster chicken."
Anzu wyliei was about 3.5 metres tall, 1.5 metres at the hip and weighed from 200kg to 300kg, the researchers said.
"It has the nickname 'the chicken from hell.' And that's a pretty good description," said chief researcher Matt Lamanna of the Carnegie Museum of Natural History in Pittsburgh.
"If you could get in a time machine and go back to western North America at the end of the age of dinosaurs and see this thing, I would say your first reaction might be, 'What a weird looking bird,'" he added. "It would not look like most people's conception of a dinosaur."
Scientists think birds arose earlier from small feathered dinosaurs. The earliest known bird is 150 million years old.
This dinosaur's bird-like traits included a beak, hollow leg bones and air spaces in its backbone.
Its bizarre head crest resembled that of the cassowary, a man-sized flightless bird native to Australia and New Guinea.
Fossils of feathers are very rare and they were not found with any of the three partial skeletons of Anzu wyliei.
But the researchers believe it had feathers based on fossils of close relatives from China that have clear evidence of them.
Anzu wyliei lived at the sunset of the age of dinosaurs, not long before an enormous meteorite is thought to have struck earth about 65.5 million years ago.
The meteorite wiped them out along with many other creatures, while sparing many birds.
It lived in a humid, warm, low-lying environment dotted with rivers and swamps that may have looked like the Louisiana bayou.
It was lush with vegetation and plant-eating dinosaurs like the horned Triceratops, armoured Ankylosaurus, dome-headed Pachycephalosaurus and duck-billed Edmontosaurus.
But also hanging around the neighbourhood was one of the fiercest predators in earth's history, Tyrannosaurus rex.
Anzu wyliei may have been an omnivore, munching on leaves, fruits or flowers while also swallowing the occasional mammal foolish enough to cross its path.
It probably needed to be careful not to end up on someone else's menu. "To a T. rex, this thing would not look like a 'chicken from hell.' It would look like lunch," Lamanna said.
The three sets of bones were found in a region famed for dinosaur remains known as the Hell Creek Formation of the Dakotas and Montana.