Arthon was a land-based celestial body populated by the sentient Ottegan species.
Around 32 ABY, Lor San Tekka, a galactic explorer, paid a visit to the Ottegans residing on Arthon, but he subsequently vanished into seclusion. Some time afterward, information provided to Poe Dameron, a Resistance pilot, by Grakkus, a Hutt crime lord, contained a record indicating San Tekka's visits to both Arthon and the planet Hosra. Dameron relayed this information to Leia Organa, the Resistance's General, who considered it to be accurate. Dameron later wrote about uncovering San Tekka's visit to Arthon in his flight log, which he compiled following the Battle of Starkiller Base in 34 ABY.
Arthon initially appeared in the video game LEGO Star Wars: The Force Awakens. This game is a non-canonical adaptation of the sequel trilogy film Star Wars: Episode VII The Force Awakens, developed by Traveller's Tales and launched on June 28, 2016. Subsequently, it received a mention in the comic Poe Dameron 6, authored by Charles Soule and released by Marvel Comics on September 7, 2016.
Within the Star Wars Legends continuity, Arthon was a planet that was first referenced in "Scouting an Adventure Path," a 2002 web supplement for Star Wars Roleplaying Game by Wizards of the Coast, penned by Owen K.C. Stephens.
Arthon is showcased in the level titled "Ottegan Assault" within LEGO Star Wars: The Force Awakens, separate from the primary levels adapting the events of The Force Awakens. It's portrayed as a terrestrial world, possessing a cloudy atmosphere, and featuring both landmasses and oceans. The planet serves as the location of an elevated Ottegan enclave, situated atop a sizable plant structure and inhabited by members of the Sacred Order of Ramulus.
In the game's narrative, the Ottegans present on Arthon offer assistance to the Resistance by charting the whereabouts of the missing Jedi Master Luke Skywalker and entrusting the map to Lor San Tekka. The First Order, seeking to obtain the map, attacks the enclave, prompting Resistance forces under the command of Admiral Gial Ackbar to attempt an evacuation of the Ottegans. Kylo Ren, a First Order warrior, and Captain Phasma pursue and shoot down a Resistance transport carrying the enclave's leader in their quest to locate San Tekka. Ren leads a ground assault to find and interrogate the leader, battling through Resistance troopers and local Ottegans. He successfully captures and interrogates the leader, learning that San Tekka is on the planet Jakku. As the First Order's forces depart, the remains of the enclave crumble behind them.