Microceratus (known as "Microceratops" before 2008) is a genus of very small, bipedal ceratopsian dinosaurs. They lived in China and Mongolia during the Late Cretaceous period, around 90 million years ago.

Microceratus in The Land Before Time

Great Hideous Beast appears

A Microceratus, referred to as the Great Hideous Beast by the characters, terrorizes a Ceratogaulus burrow in "Stranger from the Mysterious Above" for the sake of exploiting their food supply. Spike ends up frightening it away, saving the mammals.