Ephant Mon was a Chevin male from the planet Vinsoth who worked as a mercenary before deciding it was less dangerous to sell weapons as an arms dealer than it was to use them. He ended up working for the human Masse Goskey at Masse Goskey's Arms Emporium and Explosives Mart on the planet Tatooine, but by 10 BBY had killed his boss during an argument over HK8 Sawtooth blaster pistols that Goskey had wanted to sell to the Pyke Syndicate.
Mon later became head of security for the palace of his friend Jabba Desilijic Tiure, a Hutt crime lord. The Chevin watched and laughed with Jabba's other courtiers when the Hutt captured Princess Leia Organa during her attempt to rescue the smuggler Han Solo, but then warned Jabba of the danger posed by Solo and Organa's ally Luke Skywalker, a Jedi Knight. Rumor had it that Mon later avoided accompanying Jabba to the Great Pit of Carkoon, where the Hutt and many of his court members were killed by Skywalker, Organa, and Solo.
Ephant Mon was a Chevin male with a murky past who was recruited by mercenaries as a teenager to leave his homeworld of Vinsoth. He eventually changed professions to become an arms dealer and trafficker, forging a reputation for himself by selling usable but obsolete Imperial weapons to anyone who would buy them. By 10 BBY the Chevin had come to work for the unscrupulous human arms dealer Masse Goskey at Masse Goskey's Arms Emporium and Explosives Mart in Mos Eisley spaceport on the planet Tatooine. Mon was responsible for acquisitions and product inventory.
The pair at one point travelled to the moon Nar Shaddaa, where they picked up a variety of weapons that were illegal in 66 sectors. Mon also rumbled the street hood Skrrll and acquired a logbook that would later become known as the Smuggler's Guide. As Goskey had no budget to cover miscellaneous purchases, Mon began using the already partially filled book to record a vital statistics concerning the cargo that they had acquired. Goskey then added his own entry to the book criticizing Mon's recording style and complaining about the events on Nar Shaddaa, causing the Chevin to respond asking that Goskey not waste further space in the book. The pair then attended an arms deal on the planet Bonadan, where Mon also purchased a new writing stylus and a bag of finely shredded savory sweetmeats, electing to continue using the logbook he had found rather than buy a new one.
Unable to find Mon, Goskey left a note in the logbook for the Chevin informing him that he had set up a meeting on the Wheel space station with a representative of the Pyke Syndicate who wished to buy from them. Pleased, Mon organized the store's inventory in order of greatest potential profit based on Undervine demand and historical analysis of the invisible market. Goskey was angered by the fact that Mon had placed the HK8 Sawtooth blaster pistols as the least profitable items, as he believed that were the hottest items for syndicate street fronters. Mon explained the flaws of the weapon and stated that their popularity would not last, urging Goskey to heed his assessment since the Syndicate's buyer would be savvy enough to not want the pistols. Goskey ignored the advice and ordered Mon to bring as many HK8s as possible, warning the Chevin to never question him again.
The pair then got into a heated argument over the weapons and Mon, who had endured mistreatment and insults from Goskey for some time, reacted by using a HK8 sawtooth blaster pistol from the store's stock to fatally shoot Goskey in the torso. Initially Mon believed that such a wound was not lethal to humans, but later realized that he was confusing them with Ugors. Mon then successfully conducted the arms deal and planned to take over the Arms Emporium and rebrand it in his name, considering "Chevin Armorers" as one potential option. He continue to use the logbook to record inventory before a Swokes Swokes lieutenant working for him accidentally left it in a weapons crate that was purchased by Cikatro Vizago of the Broken Horn Syndicate. Vizago read Mon's entries and realized that he had been overcharged by 25 percent for what he had purchased, but wrote that there was nothing he could do about it.
Ephant Mon came to owe his life to the Hutt crime lord Jabba Desilijic Tiure after the Hutt saved him. Because of this, the former gun runner became Jabba's only true friend and due to their friendship, Mon eventually became the head of security at the Hutt's palace on Tatooine. A member of the Hutt's close circle of comrades, and a dark guest to many of the gatherings at the palace during the Imperial Era, he could often be found flanked by several of Jabba's Gamorrean bodyguards.
Mon at one point allowed an individual who was in Jabba's good graces to use the Hutt's spy network on Tatooine.
After the smuggler Han Solo was frozen in carbonite in 3 ABY, the bounty hunter Boba Fett set out to deliver the body to Jabba, who had set 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 consequence 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 not available, 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 enacted 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.
Jabba and his court then boarded the Hutt's sail barge, Khetanna, and traveled to the Great Pit of Carkoon to watch the three prisoners be fed to the sarlacc that dwelt there. Instead, the prisoners managed to free themselves before they could be executed, killing Jabba and many of his allies. Rumor had it that after warning Jabba, Mon chose deliberately not to board the sail barge and so avoided death.
Ephant Mon liked to take justice into his own hands and his massive build made him an effective fighter, with above average strength and slightly below average fighting ability, but far below average speed. Early in his life, the Chevin decided that his career would be more secure if he devoted himself to selling weapons instead of using them, as it was less dangerous. With diplomatic skills slightly below average, Mon endured poor treatment while working under Masse Goskey before finally reacting and killing his boss during an argument.
Mon was a very perceptive individual with slightly above average intelligence, who was always alert to security issues. He was especially perceptive regarding the dangers posed by Luke Skywalker and wisely warned Jabba of the threat to his security. His fears were instantly confirmed by the Jedi's arrival. Mon was recognisable by his curious appearance, characterised by his long heavy snout and dark gray skin. He also had blond hair and black eyes and stood 2.5 meters tall. He was not Force-sensitive.
Mon made use of a vibroblade and a walking stick. He wore a set of brown robes.
Ephant Mon was created for the 1983 original trilogy film, Star Wars: Episode VI Return of the Jedi, although prior to the film's release he appeared in its Star Wars Legends novelization, which was written by James Kahn. A maquette of the character was made which measured 20 centimeters by 25 centimeters by 33 centimeters. The character's costume consisted of a giant foam rubber construct that was 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.