JFO is a fan-created name for the organization led by Jason Chesterfield's father, Dargon Chesterfield, in It's Walky!, as the group was never formally named in the strip itself. The acronym stands for "Jason's Father's Organization".
The members of the JFO are from an alternate universe, where technology is more advanced than in the Walkyverse. In the process of escaping their equivalent of The Cheese, they shunted an incredible amount of energy into an otherwise normal tree branch, creating an artifact known as the Power Booster Rod.
After fleeing their original universe, the JFO used their technological superiority over the Walkyverse to establish themselves as shadowy power brokers. One of their most crucial pawns was Linda Walkerton, who was chosen by the JFO to unlock the full might of the Power Booster Rod. To accomplish this, the organization first killed her boyfriend, David, then killed Linda after she brought David to the Martian Embassy to be resurrected. Linda was then revived using Martian technology and brainwashed into wpiping out the Martians with the Rod. However, in interfering with David's revival, the JFO inadvertently created a new version of The Cheese.
Furthermore, Linda had struck a deal with the Head Alien, seeking to abduct human children and augment them with Martian DNA. In order to find all the abductees and bring them back under control, JFO created a new organization, SEMME, and placed Anthony McHenry in charge of it as the "Big Boss".
Jason apparently worked for the JFO for some time, but left due to conflicts with his father. Fellow JFO member Penny, Jason's girlfriend at the time, had no such issues, and quickly became Dargon's heir apparent after his son's departure.
When Anthony McHenry was killed, the JFO made Linda the new head of SEMME and began to brainwash her daughter, Sal Walkerton. Their ultimate goal was to manipulate Sal into eliminating the Aliens and getting the Martian technology from the Embassy. However, Sal failed in her mission, and instead led SEMME closer to the truth of their origin. To control the fallout, the JFO tapped grandstanding lawyer Bart O'Ryan to whip a mainstream media backlash blaming SEMME for the attack, leading to Sal's arrest and incarceration.
As SEMME got closer to discovering the truth, the JFO captured Squadron 135 and brainwashed all of its members save Beef into becoming double agents. At the same time, Penny and her "Britjas" attacked SEMME HQ to eliminate all traces of their existence. However, her attack was a failure. What's worse, the existence of the JFO was now known to The Cheese. To "tie up loose ends", Penny killed Dargon and assumed control of the JFO.
On the eve of the Martian invasion, Penny manipulated the US government into shutting down SEMME by leaking damaging information and creating intense pressure through Bart O'Ryan and the mainstream media. Penny then led the JFO in a direct assault on SEMME's HQ in Denver, Colorado. In the ensuing battle, her troops mostly destroyed by the Steel Duck, and she was killed by her old flame, Jason. Jason subsequently took control of the remaining Britjas, and presumably commanded them in battle against the Martians.
It is not known what happened to the remnants of the JFO after the end of It's Walky! It can be assumed that the organization was disbanded and their members arrested by the US and UK governments for the acts of terrorism the JFO members had committed on their shores.