When Korra was ready to start her airbending training, Meelo and his family traveled to the Southern Water Tribe to visit his grandmother and stay for the night. He was chewing on his father's head as the family arrived and hopped off their sky bison. When Katara took him off his father's shoulders, Meelo did not recognize his grandmother and quickly squirmed his way out of the hands of the "strange woman". He went on to play with his sisters in the snow, claiming to be a "snowbender", by using his airbending to blow off a pile of snow that covered him, showering his mother, much to her annoyance. Meelo and the rest of his family headed back home the next day, as Tenzin's duties as a United Republic Council member prevented them from relocating to the Southern Water Tribe as planned.
Meelo met Korra again not long after their last encounter, as the Avatar had run away from home and traveled to Republic City under the guise of "if Tenzin can't come to her, then she will go to Tenzin." The young boy was thrilled when he saw her again, especially after his father complied and let Korra stay on Air Temple Island in order to learn airbending with them.
As an airbender, Meelo was present during Korra's airbending training. While Korra was struggling with weaving her way through the airbending gates, he mimicked his father's advice by stating that Korra should try to "be the leaf." When Meelo participated in the meditation exercise, Tenzin singled him out as an example for Korra of how to properly meditate. However, the young boy had actually fallen asleep. Later on, when Korra destroyed the ancient training tool with her firebending in a fit of frustration and called Tenzin a "terrible teacher", Meelo instantly copied Korra's words, running around screaming and kicking the shambles of the now-broken tool.
Meelo sat quietly at dinner as Councilman Tarrlok entered and offered Korra to join his task force. He later enjoyed playing with Ikki in a new car which was sent as a gift from Tarrlok to bribe Korra. He also attended the gala Tarrlok threw for Korra along with the rest of his family, where he apparently mistook an object for a toilet, much to his father's horror and embarrassment.
Upon the arrival of Mako, Bolin, Pabu, and Asami who had come to live on Air Temple Island, Meelo immediately took a liking to the new residents. After welcoming them to "[his] domain", Meelo seemed to develop a crush on Asami, calling her pretty and asking for a piece of her hair, prompting Mako to jokingly call him "competition". Later on, when the members of Team Avatar were talking about saving Republic City, Meelo interrupted by jumping down and passing gas on their hands. He enthusiastically agreed with them, although he had no idea what they were doing, making them all laugh.
The following morning, Meelo, sleeping in the bed of his parents, awoke early to the phone ringing on a bedside table, and crawled over his father's face to reach it. He answered it and inquired who was calling, commenting that whatever it was had better have been important enough to justify waking him at six o'clock in the morning. Tenzin quickly stole the phone away from his son to take the message himself, and Meelo crawled back toward his mother.
During the Equalist attack on Air Temple Island, Meelo and his older sisters aided Lin Beifong in defeating several chi blockers. He displayed impressive talent in airbending, immobilizing several of the Equalists within moments. After the attack, Meelo joined his sisters in welcoming their new baby brother, Rohan, into the world. Shortly thereafter, he escaped the island with his family on Oogi, and watched as Lin stopped the airships from following them and got captured, stating that she was his hero, to which his father sadly agreed to.
Despite Lin's sacrifice, Meelo and the rest of his family were captured by Amon, who intended to publicly remove their bending and destroy the last airbenders. Avatar Korra and Mako swiftly came to their aid, and Korra led Meelo and the rest of his family out into one of the hallways of the Pro-bending Arena. Tenzin led his children to find Pema and Rohan, to which Meelo happily exclaimed "Prison break!", while Korra and Mako defeated Amon.
Once Republic City was safe again, Meelo returned to Air Temple Island with his family. He witnessed his boisterous Uncle Bumi enter the harbor with the rest of the United Forces, much to Ikki's enjoyment and Tenzin's embarrassment. Meelo traveled with his family, along with the rest of Avatar Korra's friends and family, to the Southern Water Tribe to have Katara restore Korra's bending. When Katara was unable to heal Korra, Meelo stood by his family, who tried to tell her it would be all right.
Meelo witnessed Korra use energybending to restore Lin Beifong's earthbending, and watched Tenzin praise Korra for her accomplishments as the Avatar. Six months after the events of the Anti-bending Revolution, Meelo took part in an air scooter race with Korra and his sisters. He came in last place.
Meelo is enthusiastic, very energetic, and is always disrupting the calmness of Air Temple Island. Like his grandfather, he is quite goofy, as shown by his rambunctious behavior and the various comical comments he makes. Meelo loves to play around and explore, and he also enjoys jumping on his father's shoulders just to pull his beard or gnaw on his head. His sporadic behavior can be useful when it comes to doling out his unique approach to airbending, such as sleeping when it is time for meditation with his father and sisters, and using airbending while flatulating to make a soft landing and knocking out chi blockers when they where invading Air Temple Island. He is also shown to be quite sassy.
Even though he is an airbender-in-training, Meelo has already demonstrated several skills. Apart from displaying a high level of acrobatics, Meelo can also levitate himself with an air spout. During the invasion of Air Temple Island, he showed remarkable skill in combative airbending, defeating six Equalists on his own. Meelo is quite agile, able to lightly jump from his grandmother's grip and flip to the ground. Several months after the Equalists' attack on Republic City, Meelo mastered the ability to use an air scooter, utilizing it in a race against his sisters and Korra.
It is also known that Meelo can use airbending to increase the effects of his own flatulence. This ability was demonstrated when he dropped in on Team Avatar after cheering Korra up, and to a greater extent during the Equalist attack on Air Temple Island.
In the German dub, Meelo was voiced by the same person who voiced Ikki and Korra.
Meelo's attire is the common clothing of young airbenders, much like the clothing worn by Aang in the first two seasons of Avatar: The Last Airbender.
Meelo was inspired by Professor Christopher Moss' son. Christopher Moss is a great friend of the co-creators; when they went to visit him in Amsterdam, his son was "crawling all over [his father]" while he calmly continued the conversation. This was later an inspiration to create Meelo's personality to "throw in the mix and test Tenzin's patience and fathering skills".
Meelo resembles an old cartoon character named Shinnosuke Nohara.
According to the creators, Meelo was originally going to be a "cute" kid until assisant director Ki Hyun Ryu said "I want him to be ugly." Co-executive producer Joaquim Dos Santos then stated that "the more ugly [Meelo] was, the cuter he became."
Oddly enough, Meelo did not recognize his grandmother, as he yelled, "Unhand me, strange woman!" when Katara picked him up.
Meelo appears to have a crush on Asami Sato.
Meelo has a tendency to jump on his father's head and even gnaw on it.
Meelo's "fartbending" was an idea that came from Ki Hyun Ryu, rather than the creators themselves.
Meelo and his siblings never met their grandfather as Aang had passed away before their births.