The Jurassic Pooch was created from a fossil that Dexter re-animated to life, however it was missing two important components: A brain and a heart. So Dexter used the brain and heart of his old dog to complete the dinosaur, but because of this the Dinosaur acted like a regular pet, much to Dexter's dismay. It appeared in the episode "Jurassic Pooch" and was voiced by Frank Welker.