The D-90 assault droid was an experimental version of the D-60 assault droid that was used by the Confederacy of Independent Systems during the Clone Wars. The were reputed to be as tough as, yet more versatile, than their predecessor design. The Separatists planned to deploy these battle droids in small teams, so that they could serve as commando units, as well as filling the role of battlefield shock troops. However, they still had some system flaws; in order to remedy this, the Separatists planned to capture the Spaarti Creations factory on Cartao to test and finalize the design. It was unknown whether their development was continued after Spaarti Creations was destroyed during the Battle of Cartao.