Original Metal Sonic

Metal Sonic was one of the deadliest robotic models created by Dr. Ivo Robotnik. He is based off his organic counterpart and Robotnik's most hated enemy, Sonic the Hedgehog. Metal Sonic was pitted against Sonic and friends on numerous occassions, finally destroyed when he chose to sacrifice himself to save Sonic and Tails.

First Encounter
Metal Sonic was first built by Dr. Robotnik so he could have his "own Sonic the Hedgehog". Metal Sonic was first put to use by Robotnik to kidnap "Sonic's Biggest Fan", Amy Rose, and bring her to the Collision Chaos Zone to be used as bait for Sonic. The mechanical copy did so, and Sonic did end up coming to the zone. The two hedgehogs then had a race around the zone's resident speed track, Stardust Speedway, with Snively (disguised as Dr. Robotnik) following them and Metal Sonic pulling tricks such as using holograms of himself. But when Sonic used his new "Figure Eight Super Peel Out" trick, Metal Sonic short-circuited while trying to catch up and exploded. (StH: #25)

Battle Against the Chaotix
When Knuckles the Echidna and the Chaotix arrived at Renfield T. Rodent's carnival to save the Freedom Fighters, Dr. Robotnik sent a rebuilt Metal Sonic to stop them. But when the duplicate realized he was clearly outnumbered, he used a Power Gem to turn into a gigantic, monstrous form. However, Heavy had his own Power Gem on hand and Knuckles used it to turn giant himself, allowing him to take on the new and improved Metal Sonic. Knuckles used his increased powers to defeat Metal Sonic, seemingly once and for all. (KCX)

Vengeance and Sacrfice
After the Freedom Fighters left Station Square, the Freedom Fighter Special almost crashed. Nate Morgan found out it was sabotaged and Sally decided to send Sonic and Tails out on reconnaissance to see if there were any signs of life. While the friends were doing this, Sonic told Tails to go find some wood for a fire. However, when Tails hadn't come back for an hour, Sonic went out to search for him. But Sonic then discovered that the person who had kidnapped Tails and sabotaged the ship was none other than METAL SONIC! The mechanical menace revealed that the Power Gem that was still inside of him when he was destroyed by Knuckles allowed him to rebuild himself. In this form, Metal Sonic could move much faster than Sonic and, deciding to give Sonic a "fair chance" to save Tails, told him that his friend was in the volcano, Mount Mobius. However, the volcano was also due to erupt soon. (StH: #85, #86)

Sonic quickly made his way to the volcano, but was stopped when Metal Sonic attacked him. However, Sonic was able to trap Metal Sonic in his own net and get to Tails before the vocano erupted. The robotic duplicate easily got out of the netting and attacked both Sonic and Tails atop the mountain. Sonic tried to tell Metal Sonic about how there's more to life than just power, but he ignored it. However, when Tails decided to stick with Sonic even while there was lava everywhere, Metal Sonic developed some sort of "conscience" and decided to hold back the lava, allowing the two to escape. Tails' actions allowed Metal Sonic to see he could be more than his programming, and as his two former foes escaped, Metal Sonic was submerged in lava, finally meeting his demise. (StH: #87)