Protectobots in the art picture.
The Protectobots are an Autobots subgroup from the Generation 1 continuity family. The Protectobots once lived on the colony world of Archon, but as the colony slowly began to fail they succumbed to stasis lock. They remained that way until Omega Supreme chanced across the ruins of the planet and brought them back to Earth. The only way to revive them was through an Energon infusion; the Aerialbots volunteered for the process. The Protectobots made a complete recovery and then some: the transfusion had given them the ability to combine! Optimus Prime gave them their own headquarters in Central City, hoping that city life would help them acclimatize to life on Earth while also providing the metropolis with an extra degree of protection.