Knuckles' personality and character traits vary between various continuities. However, he is consistently used to represent the "tough guy" or "loner," and his abilities remain roughly the same. Knuckles being tricked by Eggman into believing Sonic is the villain has become a recurring theme in the Sonic universe, even to the point of being a running gag. Although he and Sonic fight from time to time, there is an undercurrent of mutual understanding between the two. Ever since the introduction of Shadow the Hedgehog as one of Sonic's darker, more anti-heroic rivals, Knuckles' relationship with Sonic has seen as much more friendly by comparison.

Knuckles is a red echidna who protects a powerful jewel known as the Master Emerald. Knuckles is a very vital part of the Sonic the Hedgehog series. He is great friends with Sonic and he often helps him find the Chaos Emeralds. He was originally a rival to Sonic after he was fooled by Dr. Eggman. He is called Knuckles due to having large, protruding knuckles on his hands.

At times, Knuckles has a short temper, though he is very loyal, and a dependable friend and ally. He has a rivalry with Rouge the Bat, ever since she first attempted to steal the Master Emerald from under his nose. However, Knuckles mainly searches for Master Emerald pieces when it breaks (sometimes, he even breaks the Emerald to avoid having it being stolen)

Vocal Direction: (Scott Drier/Michael McGraharn)