Metal Sonic Troopers were an army of Metal Sonic robots created by Sir Charles Hedgehog and Rotor to defend Knothole against Dr. Eggman when Sonic was believed to be dead after the battle with the Xorda. Using the core programming of the original Metal Sonic and a more streamlined construction, the two of them were commissioned by King Maximillian Acorn to build an army of exactly 100 Metal Sonics, but the army was never used as Sonic returned from space before they could be activated. Sometime later, a mysterious figure (who later turned out to be A.D.A.M.) activated the army and set it loose on both Knothole and Dr. Eggman. The army even injured Hope Kintobor during their assault, resulting in a fight between Sonic and Shadow, both blaming each other over her sustained injury. However, the army was defeated when Shadow used Chaos Control, completely destroying it. Parts from the Troopers were later used in the reconstruction of Shard, the original Metal Sonic upon which they had been based. (StH: #157, #158, #159, #238)
- The Metal Sonic troopers shared Neo Metal Sonic's design from the videogame Sonic Heroes.
- Despite Dr. Eggman claiming that they were second-rate knock-offs compared to his Metal Sonic units, an observational assessment by Mecha stated that the Metal Sonic troopers were of superior design. (StH: #158) This assessment might seem inaccurate, given that Sonic was, with difficulty, able to fight against multiple Metal Sonic Troopers at once, and a single Metal Sonic has proven too much for him; however, during the battle with the Metal Sonic Troopers, Sonic had help from Shadow and they also used the Metal Sonic Troopers' attacks against each other. It might also be noted that single variants of Metal Sonic who have overpowered Sonic were either developed after the Metal Sonic Troopers had been defeated and thus possibly improved, or-in the case of Shard-had become superior to their original design.