Grenadier Crab Droid

The grenadier droid was a model of battle droid in the Separatist Droid Army that served as an effective short-range artillery platform for the Confederacy of Independent Systems during the Clone Wars.

Characteristic
Grenadier droids were designed with a small, cylindrical profile and were equipped with four, crab-like legs not unlike those of a droideka. Armed with dual grenade launchers, they were capable of launching a steady barrage of bombs at enemy personnel. They sacrificed firepower for mobility, however, as they lacked the ability to coordinate movement with attack; they could not deploy their weapons without rendering themselves completely immobile. As such, they were relegated to support roles.

History
During his Mission to Mustafar to massacre the Separatist Council, Darth Vader encountered grenadier droids flanking an Armored Assault Tank in the Klegger Corp Mining Facility.