Octuptarra tri - droid The octuptarra tri - droid , also known simply as the octuptarra droid or tri - droid and nicknamed the " virus droid " due to the biological plagues it sometimes carried , was a model of three - legged battle droid manufactured by the Techno Union . Produced in a number of different sizes , including agile octuptarra combat tri - droids and gigantic octuptarra magna tri - droids , they were used by the Confederacy of Independent Systems during the Clone Wars . Characteristics . The larger and more dangerous counterpart of the DSD1 dwarf spider droid , the octuptarra tri - droid , also known simply as the octuptarra droid or tri - droid , was a model of fourth class battle droid . Their large heads contained their cognitive modules and sensor suite . Three red photoreceptor s allowed them to look in every direction at once , leaving them with virtually no blind spots and making them almost impossible for enemy troopers to attack by surprise from behind . They had an omnidirectional field of fire , with typical octuptarra tri - droids being armed with three rotating laser cannon s placed equidistant below its photoreceptors and around its central stalk , which could spin around and lock onto targets from any side in an instant . They had three triple - jointed , hydraulic limb s that allowed them to scale steep surfaces . However , its three - legged design was its primary weakness , as if one was damaged , the entire droid would topple over . In addition , they were also slow - moving and vulnerable to tripping . Octuptarra tri - droids were produced in a number of different sizes during the Clone Wars . Agile , battle droid - sized versions , known as octuptarra combat tri - droids , stood 3 . 6 meter s in height and featured a highly - mobile chassis . Primarily used as anti - personnel platforms , certain variants stored airborne biological plagues in their bulbous heads , allowing them to wreak havoc on the enemy long after the unit is destroyed , causing them to be nicknamed " virus droids " . The largest models , known as octuptarra magna tri - droids , stood at 14 . 59 meters in height and were used as combat artillery . Large enough to take on heavily armor ed All Terrain Tactical Enforcer s , their laser cannons could be replaced with chain - fed missile launcher s . A variant of the octuptarra magna tri - droid used on the planet Skako Minor was equipped with an engine at its waist , creating enough thrust to allow it to hover many meters above the ground . The octuptarra tri - droid was named for the octuptarra , an eight - eye d , gasbag - headed walker found on Skako . History . The octuptarra tri - droid was primarily manufactured by the Techno Union division of the Separatist Droid Army , who often fielded them in battle during the Clone Wars . In the year 22 BBY , octuptarra magna tri - droids were deployed during the Battle of Christophsis , with several being destroyed due to the intervention of Jedi General Anakin Skywalker and the 501st Legion . Later in the battle , several were stationed outside of the Separatist deflector shield . In 19 BBY , octuptarra magna tri - droids were used to guard the city of Purkell , headquarters of the Techno Union , on Skako Minor . During the Outer Rim Sieges , octuptarra combat tri - droids were used to protect General Grievous ' Pau City headquarters during the Battle of Utapau . Concurrently , both variants were used by the Separatist in a battle on Mygeeto . After the Galactic Republic was replaced by the Galactic Empire , most octuptarra tri - droids were deactivated . Behind the scenes . The octuptarra tri - droid was originally created for the 2005 film . It was first identified in " " , a reference book written by Adam Bray , Kerrie Dougherty , Cole Horton , and Michael Kogge and released on September 4 , 2015 . Several variants of the octuptarra tri - droid were visible in " Revenge of the Sith " ; The octuptarra combat tri - droid found on Utapau had its digital model scaled up and modified to become the octuptarra magna tri - droid seen on Mygeeto , with slight cosmetic alterations between the two such as the former ' s laser cannons being replaced with chain - fed guns on the latter . The octuptarra tri - droid could be found in early sketches of Utapau by Ryan Church .