Hard Rock is a humanoid Ankylosaurus from an alternate reality inhabited by humanoid dinosaurs.
Hard Rock is the principal pacifist of the team.
Hard Rock is tan and wears red pants with grey boots.
After helping T-Bone stop the Raptors from enslaving his friends in "Have a Nice Daynosaur", he accidentally ended up on Earth, stranded. With no immediate way to return to his home-world, Hard Rock joined the Extreme Dinosaurs. In " Day of the Condorsaurus" he obtained his own hover vehicle.
- Hard Rock is voiced by Blu Mankuma.