Sentinels are robotic guards and soldiers for the Drakon Empire. Created by the House of War, Sentinels are the empire's primary police and military force. Their appearance makes them seem less like robots but more like living Drakons, or perhaps golems moulded to appear as such. They have a humanoid structure, closely resembling Roman centurions (though with Drakon faces) with a mohawked helmet and Roman-esque armour and skirts. They can wield a variety of different weapons but are most commonly seen wielding scythe-like staffs that can fire electrical blasts. Some Sentinels are also equipped with rocket packs for flight.
The First SentinelSonic The Hedgehog first encountered a Drakon Sentinel in the Aquatic Ruin Zone, years before his first encounter with the Drakon Empire. Unlike the Sentinels that Sonic would later encounter, this one was gigantic and made of stone, possibly created via magical means. At first, Sonic believed that the giant was a new type of Badnik, but soon discovered the truth after the giant saved him from drowning. The Sentinel explained that he was created by 'the ancient ones' and had been guarding their city for two thousand years. But as the city began to sink, they evacuated the planet and left the Sentinel behind. Realising that its work was completed, the Sentinel self-destructed and collapsed into a pile of rubble at the bottom of the lake.
Master Sentinels are giant versions of the modern Drakon soldiers. They do not carry weaponry, using their sheer size and strength to lay waste to their enemies. In the three-part story Best of Enemies, the Drakons arrived on Mobius in order to capture Sonic and sent a squad of Sentinels to the Emerald Hill Zone. Sonic easily dispatched the Drakon soldiers, but the Prosecutor commanding them summoned a giant Master Sentinel to finish the job. This Sentinel failed as well since Sonic damaged its chest armour and exposed its wiring. Tails flew Sonic into the hole and Sonic proceeded to rip the Master Sentinel apart from the inside.