Oviraptor lived at the end of the cretaceous period, about 75-65 million years ago. It was probably a very good hunter, and instead of teeth it had a very powerful beak.
Oviraptor got a reputation for being a good egg thief because the first skeleton of it was found near a nest of dinosaur eggs. The name oviraptor even means egg thief in latin. This later turned out not to be as correct as first assumed, as the eggs in the nest later proved to be eggs from the oviraptor itself and not eggs from other dinosaurs.