Sonic and friends typically encounter enemies in their adventures. This category lists them.
For most of Sonic's existence, friends of the hedgehog have battled robots known as "badniks" in the early North American and European localizations of the Sonic the Hedgehog video games. The "Badnik" term fell out of use after Sonic Adventure was released, and the robots were only referred to in-game as "Eggman's robots", with the only specified robots were the E-Series and Egg Pawn models. However, in more recent titles the badnik moniker has returned, and they now co-exist alongside other Eggman Robots.
Sonic is not restricted to just fighting robots, however. Some games, particularly when Eggman is not the main antagonist, pit the hedgehog against monsters and aliens of all shapes and sizes.
This category has the following 33 subcategories, out of 33 total.