Ephant Mon, hailing from the planet [Vinsoth](/article/vinsoth], was a male Chevin. Initially, he pursued a career as a mercenary, but he later determined that selling weapons as an arms dealer presented a safer occupation. Subsequently, he found employment under the human Masse Goskey at Masse Goskey's Arms Emporium and Explosives Mart located on Tatooine. However, by 10 BBY, an argument concerning HK8 Sawtooth blaster pistols that Goskey intended to sell to the Pyke Syndicate led Mon to kill his employer.
Later on, Mon took the position of head of security for the palace belonging to his friend Jabba Desilijic Tiure, a Hutt crime lord. When Princess Leia Organa was captured during her attempt to rescue the smuggler Han Solo, the Chevin observed and chuckled with Jabba's other courtiers. Nevertheless, he cautioned Jabba about the threat posed by Solo and Organa's ally, Luke Skywalker, a Jedi Knight. According to rumors, Mon later avoided accompanying Jabba to the Great Pit of Carkoon, where Skywalker, Organa, and Solo killed the Hutt and many members of his court.

As a male Chevin, Ephant Mon's early years were shrouded in mystery, but he was recruited by mercenaries during his adolescence, prompting him to leave his homeworld of Vinsoth. Eventually, he shifted his career path, becoming an arms dealer and trafficker, gaining notoriety by selling usable but outdated Imperial weaponry to anyone willing to purchase them. By 10 BBY, the Chevin found employment with the unscrupulous human arms dealer Masse Goskey at Masse Goskey's Arms Emporium and Explosives Mart situated in the Mos Eisley spaceport on the planet Tatooine. Mon's responsibilities included acquisitions and managing the product inventory.
The pair once journeyed to the moon Nar Shaddaa, where they acquired a range of weapons outlawed in 66 sectors. Mon also subdued the street thug Skrrll and obtained a logbook that would later be known as the Smuggler's Guide. Given Goskey's limited budget for miscellaneous expenses, Mon started utilizing the partially filled book to document crucial statistics regarding their acquired cargo. Subsequently, Goskey added his own entry, criticizing Mon's recording style and complaining about the events on Nar Shaddaa, prompting Mon to request that Goskey refrain from wasting further space in the book. Later, the duo participated in an arms deal on the planet Bonadan, where Mon also purchased a new writing stylus and a bag of finely shredded savory sweetmeats, opting to continue using the found logbook instead of buying a new one.
Unable to locate Mon, Goskey left a note in the logbook, informing the Chevin about a meeting he had arranged on the Wheel space station with a representative from the Pyke Syndicate interested in making a purchase. Delighted, Mon reorganized the store's inventory based on the greatest potential profit according to Undervine demand and historical analysis of the invisible market. Goskey became infuriated when he discovered that Mon had listed the HK8 Sawtooth blaster pistols as the least profitable items, as he believed they were the most sought-after items for syndicate street fronters. Mon explained the weapon's flaws and asserted that their popularity would be short-lived, urging Goskey to heed his assessment since the Syndicate's buyer would be astute enough to recognize the pistols' shortcomings. Goskey disregarded the advice and instructed Mon to bring as many HK8s as possible, warning the Chevin never to question him again.

The disagreement over the weapons escalated into a heated argument, and Mon, having endured mistreatment and insults from Goskey for an extended period, reacted by using a HK8 sawtooth blaster pistol from the store's inventory to fatally shoot Goskey in the torso. Initially, Mon believed that such a wound would not be fatal to humans, but he later realized that he had mistaken them for Ugors. Mon then successfully completed the arms deal and planned to assume control of the Arms Emporium, rebranding it under his own name, with "Chevin Armorers" being one potential option. He continued to use the logbook to record inventory until a Swokes Swokes lieutenant working for him accidentally left it in a weapons crate purchased by Cikatro Vizago of the Broken Horn Syndicate. Vizago read Mon's entries and discovered that he had been overcharged by 25 percent for his purchase, but he conceded that there was nothing he could do about it.
Ephant Mon found himself indebted to the Hutt crime lord Jabba Desilijic Tiure after the Hutt saved his life. Consequently, the former gun runner became Jabba's only genuine friend, and their friendship led to Mon's appointment as the head of security at the Hutt's palace on Tatooine. As a member of the Hutt's inner circle and a frequent guest at the palace during the Imperial Era, he was often seen accompanied by several of Jabba's Gamorrean bodyguards.
On one occasion, Mon permitted an individual favored by Jabba to utilize the Hutt's spy network on Tatooine.

Following the smuggler Han Solo's freezing in carbonite in 3 ABY, the bounty hunter Boba Fett embarked on a mission to deliver the body to Jabba, who had placed a bounty on the smuggler's head. However, Solo was stolen from Fett by the Crimson Dawn crime syndicate before he could reach Jabba's Palace, and as a result Jabba put a bounty on Fett himself. The bounty hunter then traveled to the palace to confront Jabba and was greeted at the entrance by the Hutt's majordomo, Bib Fortuna.
Fortuna explained that Jabba was unavailable, as he had left the palace to attend the Crimson Dawn's auction for Solo. The majordomo then suggested Fett leave as Mon and a crowd of other palace denizens emerged behind Fortuna with their weapons drawn and aimed at the bounty hunter. Fett refused and reminded those present of his reputation and that if they died fighting him they would be dying only for the sake of Fortuna. Silently, Mon and the others lowered their weapons, allowing Fett to enter the palace with Fortuna in order to see the invitation.
Fett later successfully delivered Solo to Jabba as a prisoner. Later, when Jabba's Autonomous Translator Module, Mark II translator droid mistranlated during a deal being made between the Hutt and the Black Sun crime syndicate, causing Jabba to pay double what he should have, Mon informed the crime lord of the mistranslation and its effect. This resulted in the droid being sent to the palace's droid assessement room for punishment.
When Solo's ally Princess Leia Organa of the Alliance to Restore the Republic began planning an operation to rescue him, she requested dossiers on various members of the Hutt's court from Alliance Intelligence. The largest of these dossiers covered Mon, and consisted of 22 partial bios. Communications concerning this dossier were later included in the compilation of documents known as The Rebel Files.

In 4 ABY, Organa initiated her plan and entered Jabba's Palace at night disguised as the bounty hunter Boushh. Mon was having a festive time and moving up a staircase from the palace's lower levels toward Jabba's throne room while Organa negotiated with Jabba over the size of the bounty for the Wookiee Chewbacca, another ally of Solo's whom she had brought to earn the Hutt's trust.
Jabba allowed Organa into his court, but, having been tipped off by Fett that Boushh was not who they seemed, the Hutt had Mon and other members of his court hide within the throne room and lie in wait for Organa to free Solo after she believed they had all gone to sleep that night. After an hour of waiting, Mon was relaxing when Organa freed Solo from the carbonite, after which Jabba revealed the trap, and a curtain concealing Mon and many other court members was pulled back, revealing that they blocked Organa and Solo's exit route. The Chevin was among those who laughed at the pair and made fun of them, as Solo was then taken to the palace dungeons and Organa was enslaved by the Hutt.

Following the successful ambush, Jabba and his court celebrated late into the night. However, aware of Solo's powerful allies, Mon warned Jabba about what might happen next and about the danger posed by the Jedi Knight Luke Skywalker, a friend of Solo and Organa. The Hutt ignored the warnings, and when Skywalker did arrive at the palace the next day to try and rescue his allies the Jedi was dropped into a pit containing Jabba's rancor, Pateesa, which he killed. Mon was stood by the stairs leading down to the rancor pit when Skywalker was brought back up into the throne room, and the Chevin watched Jabba sentence the Jedi, Solo, and Chewbacca to death.
Subsequently, Jabba and his court boarded the Hutt's sail barge, Khetanna, and journeyed to the Great Pit of Carkoon to witness the three prisoners being fed to the sarlacc residing there. Instead, the prisoners successfully freed themselves before their execution, resulting in the deaths of Jabba and numerous members of his entourage. Rumors suggest that after cautioning Jabba, Mon deliberately chose not to board the sail barge, thus evading death.
Ephant Mon favored taking justice into his own hands, and his imposing physique rendered him an effective combatant, possessing above-average strength and slightly below-average fighting skills, but significantly below-average speed. Early in his life, the Chevin made the decision to dedicate himself to selling weapons rather than using them, as he perceived it as a safer career path. With diplomatic abilities slightly below average, Mon endured mistreatment while working under Masse Goskey before ultimately reacting and killing his boss during an argument.
Mon was a highly perceptive individual with slightly above-average intelligence, consistently vigilant regarding security concerns. He demonstrated particular insight into the dangers posed by Luke Skywalker, wisely alerting Jabba to the threat to his security. His fears were immediately validated by the Jedi's arrival. Mon was easily identifiable due to his distinctive appearance, characterized by his elongated, heavy snout and dark gray skin. He also possessed blond hair and black eyes and had a height of 2.5 meters. He was not Force-sensitive.
Mon utilized a vibroblade and a walking stick. He wore a set of brown robes.

Ephant Mon was conceived for the 1983 original trilogy film, Star Wars: Episode VI Return of the Jedi, although he first appeared in its Star Wars Legends novelization, penned by James Kahn, prior to the film's release. A maquette of the character was created, measuring 20 centimeters by 25 centimeters by 33 centimeters. The character's costume comprised a large foam rubber construction worn as a full-body suit by puppeteer Andy Cunningham. The mask consisted of an armature covered in plaster with clay sculpted over the top by Tony McVey.
It was constructed at Industrial Light & Magic in California and then shipped to England for filming in two separate containers. The first crate held the actual costume, while the second carried a 100 foot of two-inch vinyl air hose that was needed to supply coll air and oxygen to the actor inside. An opening in the shoulder of the costume was designed to allow the Salacious B. Crumb puppet to perch atop the character's shoulder. Production stills of the two characters set up in this fashion exist, but they never interact in the film, as it was decided that the Crumb character was so much fun that he would be Jabba's pet instead. The character's production name was "Elephant Man" and the ILM creature workshop came up with the name "Ephant Mon" as a play on this. He was number 37 on the Return of the Jedi creature list, with Crumb as 37a.
The film's second draft included a scene on Jabba's sail barge in which the protocol droid C-3PO attempted to translate a conversation between Ephant Mon and the Gran Ree-Yees. The two aliens then began fistfighting, causing C-3PO to flee. Ephant Mon was swapped out for the character Saelt-Marae when the scene was actually filmed, but it was ultimately cut from the movie anyway.