Metal Sonic (メタルソニック Metaru Sonikku) is the secondary antagonist of the Sonic the Hedgehog series. He is an evil ultra-high performance Badnik version of Sonic the Hedgehog created by Dr. Eggman for the sole purpose of destroying Sonic. The brainchild of Eggman, he is by far the doctor's greatest Badnik enemy robot creation. Deployed during Eggman's operations on Little Planet, Metal Sonic confronted Sonic in battle and lost, though he would repeatedly return to challenge Sonic and his allies. Modeled with extreme accuracy after Sonic, Metal Sonic not only resembles his template but can also imitate his moves and achieve velocities matching and even exceeding those of Sonic's. While usually serving as Eggman's obedient and silent enforcer, Metal Sonic is an intelligent robot with a very dark side. A cold-hearted, aggressive, and ruthless killer, he is obsessed with proving his superiority to Sonic and eliminating him for good to the point where he has rebelled against Eggman more than once to achieve his goal. However, he always fails in the end, only to later return more powerful than before. To this day, Metal Sonic remains one of Sonic's most dangerous foes.