Knuckles

Knuckles the Echidna is a sixteen-year old red echidna from the Sonic series, and is the gurdian of the Master Emerald on Angel Island. He competed against Mario and others in Olympic events in Mario & Sonic at the Olympic Games. In this game, Knuckles acts as a power-type character, meaning he excels at games that require brute strength, such as Hammer Throw or Javelin Throw. He is also the fastest of the Power characters. In Mario & Sonic at the Olympic Games, he is voiced by Dan Green, who also voices Vector.

Profile
''Knuckles is an echidna that shows exceptional versatility despite his overall strength in Power events. He'll perform best at events like throwing and rowing, but can also provide solid competition in many other competitions that aren't as power-based.''

Mario & Sonic at the Olympic Winter Games
Knuckles is set to reappear in the game's sequel, as a power  character again. Like all the other characters he also got his own suit.

Super Smash Bros. Brawl
Knuckles also makes a cameo in the Green Hill Zone stage in Super Smash Bros. Brawl, running through the loop in the background along with Tails and Silver the Hedgehog. He also has a Trophy in the game, as do many other characters from Sonic games. Knuckles does not make much of an impact on the game, however.