Knuckles the Echidna is one of the main characters from the Sonic the Hedgehog series. He is an anthropomorphic echidna and the current guardian of the Master Emerald, a powerful ancient relic which is his solemn duty to protect from anyone seeking to abuse it. He is also the sole surviving descendant of the echidna race from the Knuckles Clan. His dominant traits are his super strength and the two spike-like knuckles on each of his hands, from which his name is derived from, which he can use to dig with and climb walls. He can also trap the wind under his dreadlocks to glide through the air.
A loner by nature, Knuckles is independent, headstrong and serious, yet gullible and short-tempered to a fault. He is entirely devoted to his duty, spending most of his time on Angel Island protecting the Master Emerald, and rarely cares for anything that is of no importance. When his friends and others are in need of his help, however, Knuckles can always be relied on being willing to leave his post and prove himself a faithful and good-hearted hero. He is also one of Sonic's oldest friends and rivals.
Though usually depicted as the guardian of the Master Emerald, he was originally described as the guardian of Angel Island's seven Chaos Emeralds.
Knuckles is the physically strongest character in the series and extremely powerful. His practically monstrous strength enables him to perform amazing feats such as punching holes right through thick steel, shatter boulders to smithereens and lift objects many times his own size and weight. His super strength seems to lie in his upper body, particularly in his arms and hands (or fists). He also possess near-maximized endurance; capable of taking some major punishment. Knuckles' punches are incredibly powerful and he can attack with Fire Punches, as shown in the games Sonic Advance 1, 2, and 3, Sonic Adventure, Sonic Adventure 2, Sonic Heroes and Sonic Battle.
Knuckles is also shown to be very fast on his feet, but still not quite as fast as Sonic or Shadow. Though some fans insist that his strength makes up for it.
Knuckles can glide in the air by apparently trapping the air under his dreadlocks, and so far he is the only one who knows how to access and utilize the powers of the Master Emerald, other than Tikal the Echidna. He can also sense the Chaos Emeralds from a distance.
Like Sonic and Shadow, Knuckles can power up into Super Knuckles using the Chaos Emeralds or the Master Emerald. Also in the comics, Knuckles has achieved the ability to access the chaos force, allowing him to perform chaos based abilities without the use of any emeralds. Unlike Sonic, Knuckles can swim. He can also 'glide' on the top of water.