The cabbage merchant was an Earth Kingdom salesman who specialized in selling cabbages, yet was constantly plagued by misfortune during his business endeavors. He continually had his cabbages destroyed or damaged after encountering Team Avatar and their enemies. However, sometime before 120 AG, he founded Cabbage Corp, a company which produces automobiles and other technologies.
The cabbage merchant traveled to many locations in the Earth Kingdom in his profession, selling cabbages out of his cart, which was repeatedly destroyed, usually by Aang when he was fleeing from a foe or some other situation, to which he would exclaim "My cabbages!"
When the cabbage merchant was trying to enter Omashu, his cart was destroyed by a troop of overzealous earthbending guards. He later obtained a new cart filled with more cabbages, only to have it be destroyed again by the Avatar and his companions when they were riding on the Omashu delivery system. Following this, he demanded "Off with their heads, one for each head of cabbage!" during their subsequent trial, but KingBumi threw them a feast instead to the merchant's shock and annoyance. His cart was destroyed for a third and final time in Omashu by King Bumi and Aang while they rode the mail system again.
At the seedy merchants pier, his cart was destroyed by Aang when he airbent the cart while being chased by pirates, causing him to yell "This place is worse than Omashu!" The cabbage merchant was among other refugees waiting at Full Moon Bay for a ferry to Ba Sing Se; while waiting, the ferry's passport attendant told him he could not bring his cabbages due to the risk of a cabbage slug infestation. The cabbage merchant was distraught at this, thinking there could not possibly be cabbage slugs on his cabbages. However, the attendant ordered his cart to be destroyed by a security platypus bear over the screams of the merchant. Nevertheless, her suspicions were proven correct when a cabbage slug was found among the cabbages. The cabbage merchant was severely traumatized by this experience and had to be carried away by the security officers.
In Ba Sing Se, an escaped rabaroo ate his cabbages, to which he responded by exasperatedly saying, "My cabb... Oh forget it," and walked off to sob over his predicament. Eventually, the cabbage merchant met Pu-on Tim, an acclaimed Earth Kingdom playwright, during his travels. As Pu-on Tim was writing a play about Avatar Aang at that time, he provided the playwright with information about Team Avatar by recounting their many encounters. Because of the merchant's considerable knowledge on the topic, Pu-on Tim later mentioned him as "surprisingly knowledgeable merchant of cabbage", one of the sources of information for his play.
During the industrial developments that took place in Republic City, the cabbage merchant eventually bid his produce-selling days goodbye and founded a company, Cabbage Corp, orientated to the manufacturing of automobiles. His son, Lau Gan-Lan, later took over its ownership.
Outside Cabbage Corp's headquarters, a metal statue of the cabbage merchant was erected in order to commemorate his first stand in Republic City. Perched atop a high pillar, he is depicted standing, while raising a cabbage in the palm of his hand, next to his cart full of cabbages.