Dinosaur

Dinosaurs were a diverse group of prehistoric reptlies that once roamed the Earth in the Mesozoic Era.

Biology
Dinosaurs were characterized in numerous shapes, sizes and forms; sauropods (massive quadrupedal long-necked herbivorous dinosaurs), theropods (bipedal carnivorous dinosaurs), ceratopsids (quadrupedal horned frilled herbivorous dinosaurs), ornithopods (bipedal herbivorous dinosaurs), etc.

In popular culture
Extraterrestrial life forms similar to and/or identified as dinosaurs include the following.
 * In the Carnivores universe, appear not only alien dinosaurs, but also alien prehistoric mammals.
 * In the Ben 10 universe, The Vaxasaurians resemble anthropomorphic sauropods, the Pturbosaurians resembled anthropomorphic pterosaurs and the Kaosseffexx Ultimasaurias resembles tyrannosaurus centipede hybrids. It's unknown if the Pturbosaurians shared the same planet as the Vaxasaurians in the reboot.
 * The Triceratons from Teenage Mutant Ninja Turtles, are extraterrestial humanoid bipedal-triceratopses. In the 2012 TV series, they were enemies of The Kraang.
 * The Kinecelerans (also from the Ben 10 universe) resemble humanoid velociraptors.
 * In the Saurians from the Star Fox universe, are anthropomorphic prehistoric creatures.
 * The Barabians from Dragon Ball, are dinosaur-like humanoids.