Velociraptor
Until the Jurassic Park books and movies Velociraptor wasn't a very well-known Dinosaur, playing, at the very best, second-stage to its larger relative Deinonychus (which isn't all that popular itself). I myself barely gave the "swift plunderer" much thought. One interesting thing to note is that the books and movies didn't portray Velociraptors very accurately at all. For one thing these dinosaurs grew to be about 6 feet long and three feet tall, much smaller than the terrors in these works of fiction. Deinonychus was closer in size, standing five feet tall, but still a far way off. Funnily enough, the only Dromaeosaurids found rivaling the size of the movie raptors were discovered after the movie came out. Utahraptor and Megaraptor both massed about the same as a polar bear and could look down at a human easily enough. Megaraptor is a South American Dinosaur of a different evolutionary line and isn't very closely related to Velociraptor despite the body-shape simularities.
This dinosaur is commonly found in Mongolia and is another Cretaceous Dinosaur. It's thought that this Dinosaur might have hunted Protoceratops or eaten their eggs, or both. Like other Dromosaurids this animal was probably a pack-hunter, teaming up to wear down and tear up larger animals. Once a Protoceratops and Velociraptor skeleton were discovered tangled together, each with wounds, apparantly having died together in a fight.