Knuckles the Echidna

An anthropomorphic echidna and the current guardian of the Master Emerald, a powerful ancient gemstone which is kept on Angel Island. Guarding it is his solemn duty to protect from anyone seeking to abuse it, as well as the sole surviving descendant of the echidna race from the Knuckles Clan. Known for his powerful and wild nature, his dominant traits are his super strength and the two spike-like knuckles on each of his gloves, from which his name is derived from, and which he can dig and climb walls with. He can also trap the wind under his dreadlocks to glide through the air. Knuckles is also one of Sonic the Hedgehog's oldest friends and rivals.

(Source: Sonic Wiki Zone)