- “ Greetings, inferior beings of Polaris. Does your life lack a sense of purpose? Do you constantly worry about finding steady income? Do you like killing stuff? Then join the Imperial Army and aid me in my humble quest for galactic domination. Here, you will travel to new places, meet interesting people, and execute them in the name of… me. ”
- ―Emperor Tachyon explaining the "benefits" of serving him. [ToD]
Traveling to planet Zaurik, Emperor Tachyon bought the Drophyds over with raritanium and they swore absolute loyalty to him. Providing them with the necessary weapons and robotic suits to become elite commandos and enforcers, which were made from stolen Lombax technology taken by the space pirates and also given by a fooled General Azimuth, Tachyon formed them into the Imperial Army in order to start the reconstruction of the Cragmite Empire until he could bring the Cragmites back to the Polaris Galaxy.
After assembling his vast war machine, Emperor Tachyon led the Imperial Army in an assault on Fastoon, the Lombax homeworld. There, he took revenge on the Lombaxes for their defeat and banishment of the Cragmites during the Great War. Drophyd enforcers laid complete waste to the planet's surface and forced the majority of the surviving Lombaxes to retreat into the Court of Azimuth. There, they managed to escape certain doom by traveling into an alternate dimension with the "Lombax Secret."
With the primary source of resistance to the Cragmite Empire removed, Emperor Tachyon was free to take control of most of the Polaris Galaxy in the name of his rising empire. The Drophyd troopers of the Imperial Army strictly enforced Tachyon's iron-fisted will throughout most of the galaxy for years, taking over world-by-world. Tachyon's empire; however, was not equal to the strength held by the original Cragmite Empire, and he would need to bring back his brethren from their dimensional prison in order to restore it.
Members of the Imperial Army traveled the galaxy via Imperial Cruisers, warships originally apart of the space fleet of the Cragmite Empire, and found entertainment provided by Emperor Tachyon on Mukow in the Imperial Fight Festival. Propaganda supporting the Cragmites and their Crowned Prince was often shown to the citizens of Polaris, including messages spoken by the Tachyon Robot and holo-vision advertisements to join the Imperial Army and find the lost "Lombax Secret."
When Emperor Tachyon eventually succeeded in his aim to bring back the Cragmites, the Drophyds fought side-by-side with them in order to eliminate Ratchet and Clank, remaking the old structure of the Cragmite Empire and having the Imperial Army in addition. With the defeat of Tachyon and re-banishment of the Cragmites at the end of the conflict, the Drophyds ceased to serve the empire and the Imperial Army was disbanded.
- Drophyd Sentry
- Drophyd Trooper
- Drophyd Defender
- Drophyd Cyclocannon
- Drophyd Turret
- Defense Turrets
- Drophyd Missile Defense Turrets
- Drophyd Gunship
- Drophyd Transport Ship
- Ratchet & Clank Future: Tools of Destruction (first appearance)