Z31, also called Viper, was an Imperial Viper probe droid. He always obeyed orders, and loved war. Viper's success on many missions got him many promotions, and soon he became Unit Commander. After Darth Vader heard of the droid's successes, he made him part of the Imperial 501st, and elite legion made of Jango Fett clones.
Viper's kill count was medium-low, but his mission success rate was more than any other Imperial droid or hired Imperial droid. In fact, after his successes earned him a promotion of Unit Commander, he was given several Dark Troopers to command, though many times he went on missions alone. His most notable one was the Battle of Hoth.
Z31 was constructed on Arkyd, an Outer Rim Territories planet that was home to Arkyd Industries around 18 BBY. They made many droids and a few bomb types. Near the end of the ever lasting Clone Wars, the company was hired by the Republic to make droids and bombs for them. Z31 was constructed on the planet in one of the numerous factories on the surface. He was first made an Arkyd probe droid, an early version of the Viper probe droid.
Z31, like many other droids of his kind, had many gadgets at his disposal, including a vibroblade and poison darts. He also had an eye in the middle which was his main one, but he also had several small ones to use for night vision and life form detecting. When he was made, the creators decided he would be the perfect test model for the Viper probe droid, which gave him his nickname.
He was then given intelligence chips, but received more than the others because he was more intelligent naturally, and had a high count of successful training missions. Although his programming told him what to do, many probe droids received extra training to see how long they would last. These missions were conducted daily for Viper as engineers gave him more experimental items that the other units didn't get.
Soon, he was sent out to the front for his first mission. Viper was assigned to a contingent of probes which were sent to Utapau to aid the 212th Attack Battalion in searching for Obi-Wan Kenobi shortly after Order 66.
Shortly after he and the other droids landed, they were given orders by CC-2224 to find the Jedi traitor. HE and the other droids split up. Having more intelligence than the others, he managed to avoid the sea creatures in the sink holes at the bottom of the chasm that they were in. Viper found Obi-Wan Kenobi in a matter of minutes, and went back up to the city to tell the information to the clone commander.
On the city platforms, a clone airborne trooper and to regular 212th troopers listened to the rest of the droids that returned, who haven't found the Jedi, and assumed that none of the others have. By the time Viper got back, no one listened to him and the troopers told Cody that the Jedi hasn't been found. Viper and the others were loaded up on the transports and taken back up to a Venator-class Star Destroyer as Cody and his men routed out the rest of the surviving CIS battle droids.
Early Imperial PeriodEdit
People underestimate me because of my size, which leads to their death.
—Z31 on his small droid body
Order 66 branded all Jedi traitors, and the Separatists army was shut down, except for several surviving rogue battle droids. Z31 and the others were sent to New Plympto, which was one of the planets that had a resistance on it. He and the others were taken down by a small transport to aid the 501st forces. The clones were outnumbered, and were getting ambushed from the sides of the canyon they were in. Their A4 Juggernauts were destroyed. Z31 and the other probes attacked. Viper killed several Plympto natives and sped off to where a Jedi was leading a charge. He attacked as soon as he saw Viper, but it was to late. The probe droid shot poison darts at the attacker's chest, instantly killing him. The clones later apprehended the rest of the enemy forces.
Soon after the rebellion on New Plympto was taken care of, Z31 and the rest of the troops and droids went up to the Star Destroyer orbiting the planet. As the ships went to Mustafar, a planet that was home to a Separatist holdout, Viper went to the rear observation deck and looked out the window, and saw a ship that was not in his databank. He plundered on what it could be on the rest of the trip to the volcanic planet.
The Clone Wars were over, but some people didn't get the message.
—Z31 during the battle
The Star Destroyer soon dropped them off at the planet. The forces attacked, and the droids were occupied with fighting the 501st stormtroopers. Z31 left the main group and went to the control room, and shut down half of the droids that were attacking. he reprogrammed a squad of magna guards to attack the rest of the CIS droids. Meanwhile, the Star Destroyers destroyed the navy in space. The new battle plan was given to the 501st commander and he had every one retreat, and the Star Destroyers released an orbital bombardment.
Afterward, a rebellion rose in Cloud City, where several followers of Galactic Senator Garm Bel Iblis rose and rebelled against the Imperial garrison. The troopers took out a few of them, but they were soon overwhelmed. Fortunately, they have been able to send a distress beacon, which was picked up by a nearby fleet. Z31, now with a new Viper probe droid body, was sent down. He easily exterminated the enemy forces there and returned up to the Star Destroyer.
After the battle was over, he went on several more missions. They were all successful, and the droid soon fell in the eyes of Darth Vader.
Galactic Civil WarEdit
As the Alliance to Restore the Republic rose, and the Galactic Civil War began, Z31's successful mission count grew, and so did his popularity. Many Imperial commanders wanted him to be part of their units, and many commanders asked Darth Vader if Viper could be transferred to their legion, but were given their death as a reply. Darth Vader than met up with the droid after his Star Destroyer docked at the same space station as the Executer. Darth Vader ordered the droid to be upgraded with more advanced technology that other droids didn't have. In no time, Z31 was the most successful droid in the Empire. Vader had the droid transferred to the 501st Legion, but after several more operations, Vader set his eyes on a different droid.
After the battle of Yavin, and the Death Star's destruction, half of the 501st were wiped out. Though he was a droid, Viper felt sympathy for the clone soldiers who died on the station, and looked for a way to get back at the Rebel scum. He heard that Lord Vader was looking for probes to search for the Rebel Base. Viper gladly decided to join, and soon was off to the Hoth System.
Z31 landed on the planet. Crash landed, actually, in a one way hyperspace pod. After the landing, he exited the pod and navigated through the snowy terrain. He also had to avoid a patrol of Rebels, which lead him to believe that a Rebel base was nearby. He searched around some more, but was found by a wampa. The creature took him into it's cave and hung him on the icy ceiling. After a short while of thinking, Z31 broke out one of his legs and turned on a small smelter, which melted the ice holding him. He quickly exited the cave before the hungry creature returned.
Never underestimate a droid.
Later, his suspicions proved right when he found the Rebels' shield generator. He quickly sent word back to the Executor, and hid behind a hill after sensing radio waves of a radar. Later, two people arrived, and he turned on a hologram of himself and projected it to the rebels. Then, he had the projection self destruct, which led the Rebels of his trail. The Blizzard Force was sent to destroy the Rebel base. Viper tried to reach the walkers of the invasion force but had to get passed Echo Station 3TA. He placed a detonator at the station, evading the soldiers there, and sped off to a nearby hill, where he watched the Rebels getting blown to bits. After that, he sped towards the walkers.
After he reached the walkers, an AT-AT mistaken him for a Rebel droid. It fired at him, destroying half of his body. Suddenly, they realized it was Z31, and came down and took him in the walker. Viper refused to get a new droid body sense he liked the Viper probe droid one, so he got a temporary replacement: a Hunter Killer probe droid body.
They soon one the battle, and Viper met up with Vader in Echo Base as the last of the Rebels retreated. They went back up to the Executor after taking out the remaining Rebel forces.