Fossilized for 65 million years, Dino Brachio sprang back to life when Earth transformed him into a Brachiosaurus-based Dino Knight. His purpose: defend the planet from the Dragozaurs, aliens intent on draining its life force. As the oldest, largest, and wisest of the Dino Knights, he serves as second-in-command to Dino Tyranno. Dino Brachio favors peaceful solutions but fights fiercely when needed, wielding the Axe of Valor (also known as the Grand Axe) with surprising agility for his size. He can also command supplementary Dino Weapons, like Dino Kenty's drill form.

Deeply loyal and protective of both his fellow Dino Knights and human allies, Dino Brachio acts as a trusted advisor in conflict and undertakes critical missions. This includes confronting Drago Clones—evil replicas of the Dino Knights. His character provides stability and wisdom throughout the series, remaining consistent without major personal evolution. After the ultimate defeat of the Dragozaurs, Dino Brachio returned to a fossilized state alongside his comrades.