The group consisted of five members, each of whom specialized in a different type of weapon or fighting style, though their preferred weapons were not well adapted for close-combat. After the Rough Rhinos became mercenaries, they allowed former members of the army to join them.
During the Hundred Year War
Around 91 AG, the Rough Rhinos attacked the village where Jet was living and killed his parents, which ignited Jet's lifelong hatred of the Fire Nation. In late 99 AG, they invaded another village at the western Earth Kingdom coast, forcing the residents to become refugees, including Tahn and Ying.
In 100 AG, the Rough Rhinos first encountered Team Avatar, ambushing them in a forest near Chin Village. The three friends did, however, manage to escape on Appa. The Rough Rhinos later invaded Chin Village during Aang's trial for the murder of the village's great leader, Chin the Great. They claimed the village in the name of the Fire Lord and had commenced their destruction of the village before eventually being defeated by Team Avatar.
Sometime later, the team of soldiers surrounded Iroh and Zuko while the two fugitives of the Fire Nation were traveling through the Earth Kingdom, near the great Si Wong Desert. After a brief battle, the warriors were bested by the two firebenders, who were able to escape in the chaos ensuing an explosion.
Guards of the Earthen Fire Refinery
After the war, the Rough Rhinos left the service of the Fire Lord, recruited three new members, and offered themselves for hire as mercenaries, eventually winding up as the personal security detail of the owners of the Earthen Fire Refinery, Lao Beifong and Loban. In this capacity, they were tasked by Lao to escort Team Avatar off the factory's premises. A fight between the two groups broke out, though, one that ended in the favor of Team Avatar.
The Rough Rhinos' leader, Colonel Mongke, was a talented firebender, although Zuko managed to overpower him without significant effort. He was the only firebender in the group and once served under Iroh in the Fire Nation military.Ogodei and Kahchi preferred melee weaponry: Ogodei carried chains or "bolas" and Kahchi a Guan Dao. Yeh-Lu specialized in explosives and wore armor that masked his face, never exposing it in any known encounters. Vachir wielded a bow and frequently used flaming arrows, making him the third member to fight with fire. He was originally a member of the renowned Yuyan Archers, as indicated by his facial tattoos. At the end of the Hundred Year War, the Rough Rhinos recruited new members into their ranks; among them was Utor, a former Fire Nation soldier.
All of the original riders' names resemble various Mongolians associated with Genghis Khan, and other nomadic warriors.
Their name bears strong resemblance to the Rough Riders, an American cavalry unit once led by Colonel, and eventual United States President, Theodore Roosevelt.
In the Rough Rhinos' second encounter with Team Avatar, Yeh-Lu was inexplicably absent.
Despite their fierce reputation, they were also a "very capable singing group", according to Iroh.
Each original rider seemed to be related to a different part of the Fire Nation military; Mongke was a firebender, Ogodei was an engineer, Yeh-Lu was a bombardier, Kahchi was a regular infantry soldier, and Vachir was a Yuyan Archer.
Although a supposedly fearsome and successful organization, they were fairly unsuccessful during their appearances in the series.