Ben, Gwen and Kevin were in a museum of Dinosaurs. At midnight, Ben unknowningly changes into Ben-Rex and caused a rampage. Gwen and Kevin were asleep. Ben controlled Ben-Rex and found that Kevin and Gwen were hypnotized by Sublimino and Animo revived the Dinosaurs. Animo made a trial of Dinosaurs where Ben is the main fighter. Ben-Rex, in the first round fights with Ceratosaurus. After that Ben-Rex battled Pachypleurosauria and won. After many round, he found out that he obtained the Dinosauria Genus Spell where he can change into any form of Dinosaurs (except the final round of Pterodactyl). Pterodactyl was too powerful. Ben changes into a Stegosaurus and then Ankylosaur which bounced right up to Pterodactyl's wings hurting him. Ben absorbed the Pterodactyl spell and was able to transform into the Pterodactyl. Ben then battled Sublimino in a sneak ball as Cannonbolt. Suddenly Gwen and Kevin woke up. They return back to Bellwood.
Ben can changes into all kinds of alien Dinosaurs.