This papercraft is the Knuckles the Echidna, based on the game series Sonic the Hedgehog, the paper model is designed by Destro2k. Knuckles the Echidna is a red 16-year-old anthropomorphic echidna, who is both physically powerful and highly resilient. He has a white crescent symbol on his chest.
Knuckles' name is derived from the four knuckles - two on each hand - which are actually sharp spikes. According to official Sonic Team polls, Knuckles is the fourth most popular character in the series, behind Tails, Shadow, and Sonic.
You can download the paper craft template here: Sonic the Hedgehog - Knuckles the Echidna Free Papercraft Download