Knuckles the Echidna is a fictional, anthropomorphic red echidna with a white crescent symbol on his chest from the Sonic the Hedgehog series. Both physically powerful and highly resilient, Knuckles is the last guardian of the Master Emerald, a powerful ancient relic which is his solemn duty to protect from anyone who wants to steal it. He initially opposes Sonic due to the mistaken belief that he plans to abuse the Emerald's power, but becomes his lifelong friend when the misunderstanding is resolved. For a long time, he was thought to be the last of the echidna race, until the Nocturnus Clan was revealed to still be active. It is very popular to ship Knuckles romantically with Sonic in fanworks, though in canon they are only friends.