Harley Keener is a Tennessee local who had crossed paths with Tony Stark when the latter broke into his garage, seeking shelter and food. Keener allied with Stark in his quest to uncover the enigmatic Extremis program, and prevent the series of associated terrorist attacks that plagued the United States. Despite being attacked by Eric Savin, Keener proved to be a useful ally, as he had tended to the Mark XLII Armor in Stark's absence and helped track down the Mandarin in Miami. Over the next years, Keener and Stark kept in touch, Stark becoming a father figure to Keener. Eleven years after he met him, Keener attended Stark's funeral after Stark sacrificed his life to defeat Thanos and his forces during the Battle of Earth.
Harley Keener was born and raised in Rose Hill, Tennessee. When he was four years old, Harley was abandoned by his father, who left in 2006 and never returned, supposedly with the excuse of going to 7-Eleven to get lottery tickets, leaving him with his mother and younger sister. At school, Keener was a member of the science club at his secondary school. He was frequently bullied by E.J..
Meeting Tony Stark
One night around Christmas, Keener became aware of an intruder in his garage and, armed with a potato gun, accosted the man. The intruder turned out to be Tony Stark, and the unexpected arrival was made even more impressive by the presence of Stark's latest prototype Iron Man armor. While discussing Stark's situation, the boy and inventor quickly developed a rapport as Keener agreed to help him.
After providing supplies, Keener brought Stark to a location that had been the site of an explosion with a rare thermal signature, and then to Mrs. Davis whose son had been the cause of the event. That meeting did not go as planned, with Stark encountering Ellen Brandt and Eric Savin, two Extremis-infused agents also intent on finding the woman. The ensuing fight spilled back outside where Savin encountered Keener and used him as a hostage to ensure Stark's compliance. Keener was able to break free from the situation using a flash grenade that Stark had supplied earlier as a bully-deterrent.
Supervising the Mark XLII
Despite Keener's earlier assistance, Tony Stark had left him by the roadside while he drove away to pursue the mysteries he was chasing. Keener's persistence in communicating with the inventor had a fortunate outcome while the two were in telephone communication. He snapped Stark out of an anxiety attack by pointing out that Stark's nature was to be a mechanic, and therefore he should simply build something. That gave Stark renewed focus and drew him back to Keener's garage to improvise a new series of gadgets with which to give him an edge while his armor was out of commission.
Present from the Mechanic
After Tony Stark left to continue his vendetta, Keener was left to continue his mundane life. Not long after the encounter with the wayward mechanic, Keener came home from school to find his garage packed with new equipment, from computers to robotics, and was overjoyed. On a table was a more personal gift with a placard that read, "Potato Gun Mark II" and regards from "The Mechanic".
Tony Stark's Funeral
In 2023, Keener attended Tony Stark's funeral at the Stark Eco-Compound. During the funeral, Keener thought that after having been in touch with Stark all those years, he had since come to see him as the only father-figure he ever had.
Keener is a young boy who is quite intelligent for his age. Even though his intelligence is not as high as Tony Stark's, Keener is smart enough to build a potato gun that shoots like an actual gun and can come up with suggestions to improve and fix the Mark XLII armor.
Keener is shown to be very talkative as he constantly annoys Stark and nearly causes him to have anxiety attacks. Keener's chatty behavior likely stems from the fact that his father left him at a young age, along with the fact of having no friends. When meeting Stark, Keener immediately grew to see the famous billionaire superhero as a father figure, followed him around, and put himself in danger to protect Stark from Extremis Soldiers. Keener even tried to get Stark to stay with him by giving him the guilt trip and using an adorable manner, although it failed. Despite this, Keener was kept in touch with Stark, helped repair his armor, and gave him advice to use his mechanical skills to fight against A.I.M. and Aldrich Killian.
Following the Battle on the Norco, Keener kept in touch with Stark who rewarded him with new equipment, from computers to robotics, in his garage and a new potato gun that said "Potato Gun Mark II". Keener's friendship with Stark would last for many years where a depressed Keener would attend Stark's funeral after the latter sacrificed him during the Battle of Earth to pay his respects to the man he considered as a father-figure.
- Engineer: Keener was able to build himself a Potato Gun at a very young age. It even impressed Tony Stark who gave him a better version as a gift for helping him.
- Marksman: Despite his young age, Keener has some skill in marksmanship. He accurately shot a potato at a glass bottle with his potato gun during his first encounter with Tony Stark and during the Battle of Rose Hill, Keener accurately threw a snow ball at Eric Savin to prevent him from shooting Stark.
- Potato Gun: Keener used a homemade potato gun that he had made in his garage when he first encountered and confronted Tony Stark, shooting a potato at a glass bottle to prove the accuracy of the gun to Stark. He was later provided an upgraded version of the gun dubbed "Mark II" by Stark.
- Keener Residence: As a child, Keener lived at the Tennessee house. When Tony Stark crashed in Rose Hill after his mansion was destroyed he broke into the family garage and met Keener. He made a deal with Stark to allow him access to the garage and several other resources in exchange for a weapon to fend off bullies. When Stark left to find and stop the Mandarin, Keener stayed in the garage to supervise the charging of the Mark 42.
- Harley Keener is the first child to be a main character in the Marvel Cinematic Universe.
Behind the Scenes
- Harley Keener was created by Shane Black, who pitched the idea of a superhero running into a little kid in heartland America, a decision which Robert Downey, Jr. opined to be "a wise choice and a calculated risk" to the storyline of Iron Man 3.
- At the suggestion of the production executive Chris Fenton, Harley Keener was at one point considered to be made a Chinese exchange student whose father transferred to the U.S. for business reasons. Fenton wanted the character to act as an homage to then upcoming leader Xi Jinping in the hopes that it will be "the ultimate cultural bridge between the world's only two superpowers". The idea was shot down because it "[felt] like an infomercial for China".
- Emily Brobst was a stunt double for Ty Simpkins in the role of Harley Keener.