Charko was a Chagrian male who functioned as the ringleader of a criminal organization called the Sarlaccs located on the planet of Gorse. The criminal made multiple unsuccessful attempts to steal from the pilot Kanan Jarrus; during the third such attempt, Jarrus snapped off one of the Chagrian's horns. Later, Charko sought revenge for this humiliation, attempting to provoke Jarrus into a fight outside of Drakka's Diner. However, he lacked the courage to enter the diner itself, fearing its Besalisk proprietor, Drakka. Subsequently, the Twi'lek Hera Syndulla contracted the Sarlaccs to stage a diversion, enabling her to extract the demolitions expert Skelly. Following the completion of the job, Charko opted to simply rob Syndulla rather than accept the agreed-upon payment. Jarrus intervened, and together, he and Syndulla engaged and overcame Charko and his crew.
About eleven years prior to the Battle of Yavin, the male Chagrian Charko was the head of the criminal enterprise known as the Sarlaccs. He and his gang conducted their illicit activities on the planet Gorse, particularly targeting pedestrians within the Industrial sector of Gorse City. On three separate occasions, Charko tried unsuccessfully to rob Kanan Jarrus. Jarrus was a Jedi in hiding who was employed as a pilot by a local mining company named Moonglow Polychemical. These three attempts all took place in an area referred to as Bogan Boulevard. During the third attempt, Jarrus broke off one of Charko's horns, prompting Charko to vow revenge for this humiliation.
The next time Charko encountered Jarrus, the pilot was dining at a diner on Bogan Boulevard. From the diner's entrance, the Chagrian issued challenges to Jarrus. However, he was too intimidated to enter the diner, fearing the wrath of its Besalisk owner, Drakka. Jarrus largely ignored Charko's taunts, and the criminal ultimately fled when Drakka began to arm himself. After retreating from the diner, Charko and at least eight of his Sarlaccs met with the Twi'lek pilot Hera Syndulla. She hired them for 100 credits to create a distraction, which would allow her to infiltrate Moonglow Polychemical's offices and rescue the demolitions expert Skelly, who was being held captive there.
After receiving half of their payment upfront, the Sarlaccs activated the entry buzzer at the Moonglow compound and then initiated an attempt to steal several of the company's hovervans. This commotion drew the attention of Gord Grallik, Moonglow's head of security, who rushed out of the compound with several of his men to confront the gang. With the security forces distracted, Hera successfully infiltrated the Moonglow compound and freed Skelly, who then escaped. The Sarlaccs also fled the scene shortly after being pursued by Grallik and his men. Once they had evaded the Moonglow employees, Charko and six of his men rendezvoused with Syndulla near Philo's Fueling Station, a cantina that was temporarily closed for repairs, to receive the remaining payment. However, instead of accepting the fifty credits, Charko decided to simply rob Syndulla of everything she possessed.
Before the Chagrian could attack his former employer, Jarrus interrupted the meeting and challenged Charko. The Sarlaccs readily accepted this challenge by drawing their weapons. Capitalizing on the distraction, Syndulla spun around and kicked Charko, causing him to fall and drop his credits. The Twi'lek then shot one of the Sarlaccs and escaped up a nearby set of scaffolding as Jarrus engaged the remaining gang members. After getting back on his feet, Charko attempted to topple the scaffolding that Syndulla was climbing. As the scaffolding began to collapse, Jarrus threw himself and Charko through a window into the Cantina that the scaffolding had been leaning against. Inside the empty building, Charko and Jarrus exchanged blows, but the pilot demonstrated superior combat skills and was able to kick the Chagrian through another window, after which the criminal remained incapacitated.
Despite projecting an image of toughness and threatening Jarrus, Charko was too intimidated by Drakka to venture inside the Besalisk's diner. He never traveled without at least six members of his gang. However, Jarrus still managed to break his horn during one altercation and later defeated him near Philo's Fueling Station. Both Jarrus and Drakka regarded Charko as an idiot. The Jedi-in-hiding also considered the description of a sarlacc—a ravenous monster consisting of little more than a mouth—to be an apt description of the Chagrian. Charko's height was two meters.
Charko's initial appearance was in A New Dawn, a novel penned by John Jackson Miller and published in 2014.