Knuckles the Echidna is a fictional character from the Sonic the Hedgehog series. He is a red anthropomorphic echidna and the last guardian of the Master Emerald, a powerful gem that balances the energy of the world. With his strong sense of duty, Knuckles is fiercely loyal and determined to protect the Master Emerald at all costs. Despite his tough exterior, he often finds himself manipulated due to his gullible nature. In the series, he plays the role of both an ally and a rival to Sonic, showcasing his impressive strength and combat skills.