|Knuckles the Echidna/|
Knuckles the Echidna is one of the main protagonists of the Sonic the Hedgehog series. In his debut, Sonic the Hedgehog 3, he started out as an antagonist, but after learning of Dr. Robotnik's true intentions, he eventually switched sides and became a trusted friend and ally to Sonic and Tails. He does, however, still maintain somewhat of a rivalry with the former, albeit much friendlier.
As guardian of the Master Emerald, Knuckles is depicted as a serious individual with strong sense of duty and responsibility who would do anything to defend Angel Island from any possible threat. However, he's also proven himself to be somewhat gullible, having been tricked by Dr. Robotnik numerous times throughout the series.