Oviraptor

Oviraptor was an oviraptoroid carnivorous dinosaur that lived in Asia (primarily in Mongolia) during middle to late Cretaceous. Like its cousins, it had no teeth, just a beak and a pair of bony prongs in its upper jaw. Despite that, it was still an active predator, hunting small animals - lizards, primitive mammals, maybe even other, smaller dinosaurs - and not stealing eggs.

The idea of Oviraptor being an 'egg thief' comes from a misunderstanding: when it was first discovered on a clutch of eggs, the eggs were assumed to belong to another dinosaur, Protoceratops, and Oviraptor was supposed to be stealing them. The fact that the Oviraptor died protecting this clutch of eggs which was its own, was uncovered only later, and helped to officialy recognize the fact that the dinosaurs (some of them) actually took care of their young just as modern birds do.

Oviraptor was a large dinosaur, but not the biggest member of its family - its cousin and neighbour, Gigantoraptor, literally towered over it, and its North American cousin, Chirostenotes, was the same size as Oviraptor itself, or maybe slightly bigger.

Like the rest of the non-avian dinosaurs Oviraptor and its cousins died-out during the K-T extinction.