Wil'm Grau was a male Human who served the Galactic Empire as a commando. He achieved the major rank around the time of the Battle of Yavin. Grau, leading a team, was dispatched to capture an experimental vessel that had been commandeered by Rebel Alliance members. Eventually, Major Grau and his team located the stolen ship within the Alashan system. The vessel was forced to crash-land on the surface of Alashan. Grau and five other commandos were positioned there, awaiting the ship's arrival. However, their primary vessel, a Star Destroyer in orbit, was destroyed by a laser weapon similar to the Death Star. Grau and his unit located the wrecked ship. They made the decision to collaborate with the Rebel hijackers to escape Alashan alive and to investigate the origin of the laser weapon, which had been fired from the planet's surface.
Grau, his men, and the Rebels, including Luke Skywalker and Leia Organa, investigated an old Rebel archaeological camp located a day's walk from the crash site. Upon reaching the camp, they were attacked again by the laser. Skywalker intervened, pushing Grau out of the beam's path, saving his life and earning his trust. The team briefly examined the camp, discovering the deceased Rebel researchers, before descending into the tunnel they had excavated before their deaths. The tunnel led them to a massive underground city. The Sentinel, the creature responsible for the earlier laser attacks, followed the group. Organa and Skywalker determined that the advanced computers at the city control center powered the Sentinel. They destroyed the computers, which resulted in the creature's demise. Grau, along with the only other surviving Imperial, Anarine, assisted the Rebels in repairing the damaged ship. They then departed from the planet, eventually going their separate ways.
Wil'm Grau, a male Human Imperial officer, held the rank of major by 0 ABY. In that year, he participated in the interception of communications concerning the Staraker, an experimental Imperial starship that had been hijacked. The Rebels Luke Skywalker, Leia Organa, and Mici Shabandar, along with the droids C-3PO and R2-D2, stole the ship from the planet Foundry. As the Staraker passed through the Alashan system, it sustained critical damage from a superlaser beam originating from the surface of Alashan, similar to the Death Star. An Imperial Star Destroyer pursuing the Staraker was also struck and completely destroyed. Six Imperial commandos, led by Major Grau, arrived in a smaller vessel ahead of the Star Destroyer and landed on the planet's surface. From their vantage point, they witnessed their capital ship being obliterated in orbit shortly after its arrival by the superlaser.
Upon their arrival on the planet, the crew sought out the Staraker, which had also been damaged and crashed on Alashan. After locating the Staraker, partially buried due to its crash landing, Grau and the other Imperials first saw Skywalker emerge from a tunnel he had created to reach the surface. They immediately identified him as a member of the Rebel Alliance because of his lightsaber, which he had used to dig the tunnel. Leia Organa then appeared from the buried vessel shortly afterward. At that point, Ensign Kyril Lopaki, one of Grau's comrades, wanted to take them prisoner upon recognizing Organa. Grau, in anger, told him that their survival depended on cooperation and offered the Rebels a truce. Recognizing their precarious situation, the Rebels felt they had little choice and agreed to collaborate with the stranded Imperials to escape the planet.
After traversing the planet's rugged terrain, the Imperial commandos and the Rebels arrived at an old archaeological base previously used by the Rebel Alliance, which had been destroyed by an unknown force. Grau explained their predicament to the Rebels as they reached the site, observing it from the crest of a large hill. At that moment, Skywalker sensed something in the Force and pushed the major down from his position. A laser beam struck the exact spot where the commando had been standing just seconds before. A second shot triggered an avalanche, forcing the Rebels and Imperials to rush down the hill to avoid being crushed. Boaz, one of the stormtroopers in their group, broke his leg and was unable to escape in time, resulting in his death. Leia helped dig Grau out from under some fallen rocks, and the major expressed his gratitude to Skywalker for saving his life. As a gesture of trust, he returned Skywalker's lightsaber, which the Imperials had taken from him earlier.
Skywalker pointed out that the lasers were striking from behind them, indicating that their attacker had located the Staraker. He wanted to return to the ship, as they had left the wounded Mici Shabandar there. However, the major tried to dissuade him, arguing that they would be unable to fight off their attacker. Leia also noted that the ship was a full day's march away. Their conversation was interrupted when another laser beam struck the Staraker in the distance, further burying it. The team then decided to proceed to the old Rebel camp.
The team investigated the Rebel camp and found the corpses of the Rebels who had worked there. Leia discovered a journal kept by the Rebels, which stated that they had discovered an underground city and intended to enter it. Grau stated that they would not find the answers to their problems at the base and jumped into the tunnel the Rebels had excavated, leaving the stormtrooper Eger Djambo as a rearguard. The team discovered more Rebel corpses and eventually found a breached metal barrier leading into the city itself. Meanwhile, on the surface, Djambo was killed by the Sentinel, the creature that had attacked them earlier and was hunting them.
As they entered the city, Grau expressed his unease and decided to call Djambo. They realized he was dead when the trooper did not respond to their attempts to contact him. The major left a stormtrooper named Voss behind to guard the bridge connecting the city with the cave tunnel they had entered through. Voss was killed shortly afterward as the Sentinel arrived in the city. They all fired their blasters at the beast, but it appeared to be impervious to the shots. However, some of the shots deflected off its hide and struck the nearby tunnel walls, destroying the rock and causing the tunnel to collapse onto the Sentinel. Assuming it was dead, they entered the city, but the Sentinel had survived and continued its pursuit.
The creature attacked Skywalker and Organa, knocking them off a ledge. However, they managed to use a grapple to reach a nearby platform. Meanwhile, Grau and one of his only surviving commandos, Fleet Sergeant Anarine, were pursued by the Sentinel through the city streets. The two Imperials attempted to lure it into a building rigged with explosives to kill it, but the creature survived and continued to chase them. They were cornered in a dead-end alley when the creature suddenly vanished. The major was unaware that the Sentinel had teleported to the control center, where Skywalker, Organa, and Ensign Lopaki discovered the computer consoles that powered it. The Sentinel killed Lopaki before the Rebels destroyed the computers, weakening the creature and resulting in its death.
Several days later, the small group recovered the Staraker, made basic repairs, and departed the planet together. As they flew off, Organa asked Grau to join the Rebellion, calling him a "man of honor and principles." The major asked for time to consider it with Anarine. The two Imperials later left the Staraker in its scout boat. At that point, Grau contacted the Rebels and told them that he and Anarine belonged with the Empire.
Grau was an experienced soldier who led a small team of stormtrooper commandos. Unlike Ensign Lopaki, one of his men, he was not a zealous Imperial patriot. He prevented Lopaki from handcuffing the Rebels when they encountered them at the downed Staraker. No one in the commando unit openly disagreed with his opinion that they needed to work with the Rebels. When Skywalker later saved the major from being hit by the Sentinel's laser beam, he began to trust the Rebels and returned the lightsaber that the Imperials had taken from them earlier, stating it was a sign of his trust. However, he remained loyal to the Empire, refusing Organa's offer to join the Rebellion and leaving the Staraker with the only surviving commando from his team.
Grau, a middle-aged Human male, had brown hair and a large beard. Instead of wearing a standard Imperial officer's uniform, he wore a red tunic, a yellow shirt, and a cap.
Major Grau appeared in The Word for World is Death! and The Guardian of Forever!, issues of the Marvel Star Wars Weekly comic series published in April 1980. He was later mentioned in The Complete Star Wars Encyclopedia.