Knuckles the Echidna is a video game character who appears in the Sonic the Hedgehog series released by Sega. He also appears in spin-off games, comics, and a feature film. His debut appearance was in Sonic the Hedgehog 3, released in 1994 to introduce a new rival for Sonic. He was presented as an antagonist who was tricked by Dr. Eggman into fighting Sonic. But after discovering this, he has been friends with Sonic since then. Knuckles is a 16-year-old red anthropomorphic echidna, who is both physically powerful and highly resilient. In most Sonic games, his skills include climbing on ledges or walls and gliding in the air for short periods of time. He has a white crescent on his chest and four knuckles total, two on each hand, which are overgrown bones. He is both a friend and a rival to Sonic.