Parasaurolophus walkeri, a late Cretaceous hadrosaur with a particularly handsome head crest. The crest might have been used as a resonance chamber.
When I was a kid, I used to have a plastic toy Parasaurolophus that had green body and a red crest. They even had the same colouring in Dinotopia. Ever since I've felt this is the only way to reconstruct a Parasaurolophus: all the other colour themes just look wrong.