The NR-N99 Persuader-class droid tank - often referred to as the "snail tank" is a heavy-duty battle droid from the twilight years of the Galactic Republic in the Star Wars universe. Manufactured by the Techno Union, the snail tanks were deployed by the Confederacy in many campaigns during the Clone Wars.
The tank droid was a six-meter tall automaton with a huge, central drive motor for locomotion supported by four small outrigger wheels. It could also roll on its single traction drive tread. The tank droid was also equipped with a pair of large outrigger arms connected to either side of the drive motor which could be armed with almost any weapon. The Persuader-class's front featured several sensors above its twin photoreceptor eyes. Because of its forward drive motor, the tank droid was not an especially maneuverable vehicle and was very easy to engage when being flanked. To compensate for this, the tanks deployed in tightly packed waves, forming a wall of armor. At a speed of 60 kilometers per hour, the tank had no trouble ramming through walls and mowing down obstacles in its way. Civilians particularly feared the NR-N99 because unlike the IG-227 Hailfire-class droid tank and OG-9 homing spider droid, which would generally avoid civilian targets, the tank droid would simply crush everything in its path with merciless precision.
Before the Clone Wars, the tank droid was deployed by the Corporate Alliance against Outer Rim worlds that opposed its development plans or protested against its unfair business practices. It was one of the contributions of the Corporate Alliance to the droid armies of the Confederacy of Independent Systems.
During the Clone Wars, the droid enforcers were equipped with conventional ion cannons and heavy rapid fire laser cannons. For special missions, these could be replaced by concussion missile launchers, homing missiles, dumbfire torpedoes, and thermal grenade launchers. The tank droids were used to accompany larger vehicles such as the Hailfire-class droid tank or OG-9 homing spider droid. In most battles, a pair of NR-N99s would work together to protect a homing spider droid, though three droid tanks were required to adequately defend a Hailfire-class droid tank. The droid enforcer, with its huge central wheel, could also crush to death any unfortunate enemy soldier that got into its path. The Corporate Alliance installed voice modulators into the Persuader-class late in the Clone Wars. A few variants were lucky enough to have passenger space replaced with defensive laser cannon turrets to help destroy enemies if it should be flanked.
The Corporate Alliance tank droids participated in the Battle of Geonosis, and many other battles during the Clone Wars, such as the Battle of Thule in the Dark Reaper Crisis, although they were lesser used than other Separatist armor. NR-N99s also participated in the Battle of Kashyyyk, where, in the role of spearheading an armored assault, they formed the bulk of the Separatist mechanized forces.
Following the execution of the Separatist Council by Darth Sidious's new apprentice, Darth Vader, all NR-N99 droid enforcers were de-activated.