Commander Zeta Traal, a Human female officer in the Imperial military, served the Imperial Diplomatic Corps on the world of Velmor during the Galactic Civil War. As a diplomatic aide to the royal regent, Zelor, she was tasked with ensuring Zelor's governance aligned with Imperial directives. Three years following the Battle of Yavin, Prince Anod, the current royal successor, was preparing to be crowned and assume control of Velmor from Zelor as the planet's new monarch. While Anod was loyal to the Galactic Empire, neither Traal nor Zelor intended for the prince to hold power for an extended period. The situation grew more complex with the arrival of Anod's elder brother, Prince Denid, on Velmor after two decades in exile. A hunter of bounties named Korl Marcus located Denid on Tantajoc V and brought him back to Velmor so that he could rightfully assume the position of heir to the throne. Korl Marcus was, in reality, Luke Skywalker in disguise, working for the Rebel Alliance to install a sympathizer of the Rebellion as ruler.
Captain Traal believed Korl Marcus was the kind of bounty hunter whose loyalty could be bought by the highest bidder. She tried to charm Korl one evening, offering him compensation if he would consent to murder Prince Denid. Luke never intended to comply with Traal's request, but he agreed to the scheme to protect his true identity. Skywalker cautioned Denid about Traal's machinations during a Mrid Hunt, causing the plot involving Traal, Zelor, and Anod to unravel. As events descended into chaos, Traal fatally shot Prince Anod in the chest. She then aimed her weapon at Skywalker, but a Velmoc named Jedidiah jumped on her, disrupting her aim. Traal spun around and discharged a shot at point-blank range directly into Jedidiah's chest, killing him. By this time, Denid, Luke, and the others had gained the advantage, and Traal was apprehended.

Zeta Traal had achieved the rank of captain within the Imperial Diplomatic Corps by the time of the Galactic Civil War. As an Imperial diplomat, Traal's assignment was on the planet of Velmor, where she oversaw Imperial interests. Years prior, Imperial agents had instigated a Great Revolt on the planet to overthrow the reigning monarchs, King Lorac and Queen Denira, with the goal of installing rulers who would support the Galactic Empire. However, their son and heir, Prince Denid, had fled the world following the uprising and vanished. Velmorian tradition stipulated that a royal heir must be declared dead after twenty years, and the Imperials instated the Velmorian, Zelor, as Regent until Anod, the Imperial-sympathizing second son of the deposed monarchs, could be legally declared King.
While serving as a diplomat to Velmor, Traal developed relationships with Zelor and the heir-apparent, Prince Anod, gaining their confidence. As part of the diplomatic corps, Traal prepared a report on the world for her superiors, requesting an extension of her assignment on Velmor so she could influence Anod after he ascended to the throne. In her report, Traal provided a profile of the native species of Velmor, the Velmoc. Displaying humanocentric speciesist views, Traal recommended that after Anod became King, the Empire should bombard the Tol Velmoc mountains, where the majority of the Velmoc resided. Traal hoped this action would eradicate the Velmoc and serve as a warning to the Human Velmorians of the Empire's power. Upon sending her report, Traal underestimated Velmorian intelligence, and the Toyal Spymaster intercepted her transmission.

By 3 ABY, the required twenty years had passed since Prince Denid's disappearance, and the Velmorians were preparing to pronounce Denid deceased and crown Prince Anod as their new King. On the day of Anod's coronation, the ceremony was interrupted by a starship that landed in the middle of the proceedings. Emerging from the ship was the missing Prince Denid, accompanied by his betrothed, the Alderaanian Loren. Denid had been discovered stranded on the planet Tantajoc V by the bounty hunter Korl Marcus and had returned just in time to assert his claim to the throne. Traal was taken aback by Denid's reappearance, disrupting the Imperial Diplomatic Corps' plans for Velmor. Zelor demanded that the royal physician, Chozz Wardle, examine Denid to verify his identity. The tests confirmed his identity, but Traal was suspicious of the timing of his return, suspecting a larger scheme was underway. Unbeknownst to Traal, Korl Marcus and Lady Loren were aliases for Luke Skywalker and Leia Organa, agents of the Rebel Alliance. Skywalker and Organa had orchestrated Denid's return to prevent Velmor from falling under the Empire's control.
During the celebration of Denid's survival, Traal was seated next to Korl Marcus, and his presence sparked an idea for a plan. Captain Traal knew that Denid had to be eliminated, and she realized that Marcus could assist her. Traal investigated Marcus' registration papers and discovered that "Korl Marcus" was a false name. However, instead of recognizing the true purpose of the alias, Traal assumed that "Marcus" was attempting to conceal a criminal past. With this information, Traal approached "Marcus" with a proposition. In exchange for keeping his false identity secret and doubling the reward he expected for rescuing Denid, Traal requested that "Korl Marcus" assassinate Prince Denid and Lady Loren. To ensure Marcus' cooperation, Traal promised a romantic encounter and demonstrated her sincerity by kissing the bounty hunter. "Marcus" agreed to her proposal, leaving Traal satisfied.
The Imperial captain then convened with Zelor and Anod, revealing to her fellow conspirators her plan to eliminate Marcus after he had carried out the assassination. Zelor confirmed that Anod would be prepared to assume the throne after the assassination, and Traal threatened the young prince, reminding him who was in control. Anod attempted to assert his authority, but Traal silenced him, emphasizing that Imperial power was the sole reason Anod was poised to take the throne. Zelor silenced his ward and assured Traal that they would be ready the following day after "Korl Marcus" had killed Denid. Unbeknownst to Traal, Luke Skywalker had no intention of honoring his alter ego's agreement and revealed Traal's plan to Prince Denid and Leia Organa.

The following day, Traal participated in a ceremonial Mrid Hunt and watched as Prince Denid and Lady Loren disappeared into the Great Forest of Lorac. Riding atop ycaqt beasts, Captain Traal followed "Korl Marcus" as he trailed the prince. Spotting Denid and Loren relaxing in a clearing, "Marcus" had a clear shot at Denid, and Traal urged him to take it. Instead, the bounty hunter drew his blaster pistol on the Imperial captain. To Traal's astonishment, Marcus attempted to lead her out of the forest, revealing that he would not be fulfilling their agreement. However, Zelor and Anod disrupted the capture, and Zelor shot the pistol out of the bounty hunter's hand. As Traal watched, Anod shot Denid and Loren. Enraged, "Marcus" revealed his identity as Luke Skywalker and drew his lightsaber, severing the blaster from Anod's hand. With the assassination attempt seemingly complete, the conspirators turned on each other, vying for the throne of Velmor. Zelor fired on both Skywalker and Traal, who dove out of the way of his attack. Traal returned fire and struck Anod in the chest, killing him instantly. Amidst the chaos, Traal, Zelor, and Skywalker vanished into the foliage.
As the three attempted to outmaneuver one another, Zelor was the first to gain an advantage. He spotted Skywalker meditating in the Force and approached him with his energy sword, intending to impale him. Traal observed from a distance as Zelor's attack failed, Skywalker sensing the attack and destroying the regent's weapon with his lightsaber. With the distraction, Traal aimed her weapon at Skywalker and Zelor, intending to stun Skywalker and kill Zelor. She would then be able to escape off-world with Skywalker as her prisoner. However, Traal's plan fell apart when she was ambushed by Jedidiah, a Velmoc servant of Prince Denid. The Velmoc leaped from a ycaqt beast and tackled Traal, but not before she managed to fire a single blaster shot. Jedidiah was killed instantly, but Jedidiah's sacrifice gave Skywalker the time he needed to defeat Zelor and gain the upper hand. As Traal reached for her blaster, Skywalker struck her over the head with the hilt of his lightsaber, rendering her unconscious.
Captain Traal's assassination attempt was a complete failure, as Anod had only stunned Denid. Prince Denid then had Traal arrested and placed under heavy guard. Knowing that Traal would reveal the location of Skywalker and Leia Organa, Denid promised to keep her imprisoned until the Rebels had departed Velmor. Skywalker and Organa then left Velmor, leaving Traal to the Velmorians.

Zeta Traal was an ambitious Imperial captain who aspired to climb the ranks of the Imperial Diplomatic Corps. She recognized an opportunity for advancement by promoting Imperial interests on Velmor and skillfully integrated herself into the lives of Regent Zelor and Prince Anod. Traal was willing to employ assassination and betrayal to achieve her objectives, and she attempted to use both to eliminate the rightful heir to the throne of Velmor. Traal was proficient with a blaster pistol, and she killed both Prince Anod and the Velmoc Jedidiah with precise shots from her weapon.
Traal was a supporter of High Human Culture and held humanocentric speciesist beliefs. She viewed the local Velmoc on Velmor as an inferior species. She expressed disdain for the sentient Velmoc and hoped that the Imperials would eradicate their species after gaining control of Velmor.
Captain Traal was conceived by Mike W. Barr and illustrated by Walt Simonson for use in Marvel's Star Wars (1977) 49. Traal was captured at the conclusion of the issue and did not reappear in subsequent comics.
In March 2003, Traal was mentioned in the online supplement Velmor: Royalty and Rebellion by Cory J. Herndon. Alongside information about the planet Velmor, the article revealed Traal's first name, Zeta. Traal was referenced in the article "ComicScan: Luke-ing for Love in all the Wrong Places" in Galaxy Collector 7, which referenced Skywalker's romantic encounter with Traal. She was also mentioned in the Star Wars Insider 91 article "Comic Marvels," which identified her as one of the antagonists in The Last Jedi, which was highlighted as one of the best stories from Marvel's Star Wars comics.