An Abyssin hailing from Byss, Myo had a passion for fighting. Boasting expertise in survival skills and remarkable regenerative abilities, Myo was a formidable Abyssin. On the day that Jedi Master Obi-Wan Kenobi and Luke Skywalker found themselves embroiled in a cantina brawl with Ponda Baba and Cornelius Evazan at Chalmun's Spaceport Cantina on Tatooine, Myo was present. He was an employee of the Galactic Outdoor Survival School.

Employed by the Galactic Outdoor Survival School, Myo was a male Abyssin originating from Byss. During the Galactic Empire's reign, he spent time in the Mos Eisley spaceport situated on the desert planet of Tatooine. There, he was a regular at the table of Sakiyan bounty hunter Djas Puhr in a niche near the bar within Chalmun's Spaceport Cantina, alongside thieves Muftak and Kabe, and the Bith Lirin Car'n. Myo mistook Muftak's name for his species, the Talz, and began calling the thief "the Muftak," a moniker that remained. One night in 0 BBY, Myo, Car'n, and Muftak engaged in a sabacc game, gambling at their table. Myo accumulated a significant debt to Muftak and Kabe during the game, but after winning a kloo horn from an intoxicated Car'n, the Abyssin celebrated by drinking until he became irritable and then departed without the horn. Intending to recover his debt from Myo, Muftak took the horn, but after he fell asleep, Kabe took it from the Talz and then pawned it to the Scrapper for rent money for her and Muftak.
The next morning, Myo discovered the horn was missing, leading him to shout, growl, and seek something to kill. He then spent what he claimed were his last credits to hire Puhr to locate the thief, stipulating that the deal was void if the Abyssin found and killed the target first. Car'n, also wanting to recover the horn, learned of Myo's loss and likewise hired Puhr to find the instrument, agreeing that they would let Myo handle the thieves while Car'n retrieved the horn. Meanwhile, Muftak awoke, initially hazy about the previous night but certain that Myo owed him money, though unsure how to ask such a violent individual for payment. He then remembered the horn before discovering that Kabe had sold it, at which point the Talz warned the Chadra-Fan that Myo would eat her for such a theft.
Myo then located the Scrapper but discovered that the kloo horn had already been pawned. After screaming at the pawnbroker, who was unconcerned by the threats, the Abyssian paid him twenty credits to learn that Puhr had bought the instrument, although he refused to believe that the Sakiyan had paid three hundred credits for it as the Scrapper claimed. He then paid another twenty to learn who had sold the horn to the Scrapper, and worked out that it had been Kabe based on the description given. He then mentally added forty credits to what he would demand from Kabe, although this act of mathmatics took him some time, which made him even madder.

Subsequently, Myo found Kabe in the tunnels she inhabited, shaking the Chadra-Fan by the neck while emitting guttural snarls and roars. He yelled at her, demanding an explanation for the theft, eventually realizing that the squeaking thief couldn't respond while his fist was constricting her airway. He released her to the floor, where Kabe denied stealing the horn, blaming Muftak instead. Recalling the Talz's scent from the previous night, the Abyssian pounded the wall above Kabe's head with his massive fists, showering the cowering Chadra-Fan in dust. Myo then declared he would kill Muftak, before very slowly coming to the realisation that he had actually owed the Talz money. Sliding down the wall opposite Kabe, he bemoaned that the Talz still should not have robbed him before getting up and leaving in order to find Puhr and stop him from hunting down either of the thieves.
Myo and Kabe then made their way to the cantina, joining Puhr and Car'n at their usual table. Muftak arrived shortly after, admitting to Myo that he shouldn't have taken the horn despite the debt. Myo angrily agreed, noting that he might have had the money to pay the Talz, although when Muftak question the Abyssian on if he actually had possessed the money to pay, Myo lied by responding that he might have. Car'n then pointed out that Myo had taken advantage of his drunkness to win the horn in the first place, which Myo laughed about, although none of the others joined him. They then all bemoaned their collective bad luck, with Muftak especially worried about a shipment of medication he had been unable to deliver to the criminals Doctor Cornelius Evazan and Ponda Baba, a discreet arrangement that he was shocked to learn that Myo and the others were already aware of.
Car'n then revealed that Evazan and Baba were going to back the bounty hunter Greedo, to whom Car'n was indebted, in an attempt to claim the bounty on the smuggler Han Solo. As Kabe then left to get a drink, the group looked up and watched the local moisture farmer Luke Skywalker arrive at the cantina with the hermit Obi-Wan Kenobi and the droids R2-D2 and C-3PO. Muftak then began apologizing to Car'n for not looking out for his friend in regards to the horn, with Myo interrupting the apology until Puhr stopped him. When Puhr then interrupted the Talz to claim he was an animal, Muftak called the Sakiyan a pedant, but Myo surprised everyone by correcting Muftak and calling Puhr a know-it-all instead. The Abyssian then continued, claiming that rather then being friends, all of those at the table were just potential sources of money to each other and admitting that while he knew what the horn had meant to Car'n he had still taken it and would take it again.
Puhr disagreed with Myo's assessement and made a wager that Solo would survive the day because he had friends and Greedo had none. If he won he would pay Car'n's debt to Myo, Myo's debt to Muftak, and Muftak and Kabe's debt to the bartender Ackmena, too who they still owed rent. If he lost, the Sakiyan predicted that Greedo would kill Solo and inflict great pain on Car'n, Evazan or Myo would kill Muftak, Myo would then also work out Kabe's role in the pawning of the horn and kill her as well, and he would be left looking for a new cohort to spend time with. Myo and the others realised his assessement was correct, after which Muftak apologized again to Car'n and also to Myo and then left to tell Evazan he did not have the shipment he owed him.
Before Muftak had a chance to speak to the doctor, Evazan and Baba started a fight with Skywalker and Kenobi at the bar, resulting in Kenobi maiming the criminals with his lightsaber. Surprised at this turn of events, Muftak returned to the table where Puhr got up so that Muftak would take the corner seat, keeping him and Kabe pinned between Car'n and the still angry Myo. As they discussed the current events, the group listened to Figrin D'an and the Modal Nodes, a band playing in the cantina. When Car'n, who was a member of the band, complained that he should be playing with them, Myo mistakenly thought that Car'n instead wanted to join the fighting and became excited. Car'n corrected him and then complained that he hated being a musician before being interrupted by the sound of Solo shooting Greedo dead in one of the cantina's booths. Myo from the table to see the source of the noise before turning back. With Puhr having won his bet, Muftak pointed out that he now owed all of them money, to which the Sakiyan smiled and pulled out the kloo horn from beneath the table, which even Myo admitted was a funny joke. The friends then played sabacc again together that night, with Muftak pleased that friends did sometimes take care of each other, even in Mos Eisley.

Myo, a survival expert with a penchant for violence, was a tough individual who relished fighting and carried a chip on his shoulder. Intellect wasn't his forte, and he often found himself confused, though he was aware of his own limitations and unimpressed by them. A master of directing anger towards others, the Abyssin exuded a wellspring of dark, embittered emotions when confronting Kabe. However, upon realizing his debt to Muftak, he decided to save him from Puhr, despite still harboring anger towards the Talz.
He was a terrible liar and believed that the group he often spent time with were nothing more than financial opporunities to each other, although he later apologized to both Muftak and Car'n for his part in the kloo horn caper. Myo had green skin, a single black eye, and white hair including muttonchops. He possessed self-regenerating abilities.
Myo was seen wearing a brown tunic while at the cantina.
Myo debuted in the original trilogy film, Star Wars: Episode IV A New Hope, released on May 25, 1977. According to the fan website Aveleyman, Phil Tippett, a make-up artist and stop motion animator for the film, portrayed Myo without receiving credit. His scenes were filmed during additional photography in post-production, where supplemental footage was created for the cantina sequence on a sound stage in Dovington's Hollywood studio between January 24 and 25, 1977. The character's hands were originally created by makeup artist Rick Baker for the 1974 horror film It's Alive, with the same design but modified with fur used for the Gotal cantina patrons Feltipern Trevagg, Hennet Kayn, and Cobb Sonbepol.
The character's mask started out as a mass-produced Halloween mask created by Baker and based on the cyclopean centaur character from the 1973 film The Golden Voyage of Sinbad, for which Baker hoped to get a license. When the license to use the character was turned down, the mask was then heavily modified for use in Star Wars with Laine Liska adding a number of warts one-by-one and turning it into a slip-on mask with slight articulation in the eye that allowed it to open an close, but limited articulation elsewhere. The same mask was later used in the The Star Wars Holiday Special in 1978 for which it was modified with additional hair and used for the character Cyceyed.

During the making of the film, Myo was referred to as "The One-Eyed Cyclops" or simply "Cyclops," with plans to officially name him Cyceyed in 1978; however, this name was ultimately unused for the character. Within the current Star Wars canon, Myo's identity was first established in the mobile card game Star Wars: Force Collection, which initially launched in 2013. Although the launch of Force Collection predates the Star Wars canon reset of 2014, Lucasfilm Story Group member Leland Chee confirmed that the game was kept updated to fit with canon.
The name originated in the Star Wars Legends continuity, where in June, 1995 an Abyssian character named Myo was introduced in Alliance Intelligence Reports, a supplement for Star Wars: The Roleplaying Game published by West End Games, but the book did not connect this character to the Abyssian seen in the film. In December, 1995, a card in the "Premiere Limited" set for the Star Wars Customizable Card Game produced by Decipher then identified the film character as being Myo. The name Cyceyed was then applied to The Holiday Special character that re-used Myo's mask by The Star Wars Holiday Special Cantina: Who's Who, a StarWars.com article written by Tim Veekhoven and Kevin Beentjes and published on December 2, 2013.