A Unit and J Unit are rapidly-aging genetic clones of Adam Lyon and Jake Spidermonkey, respectively. They are clones created by Jake, assigned to do all their schoolwork for him and Adam, but they went rogue and caused chaos in school, which got their creators in trouble. They are one-time villains from the Cartoon Network original series My Gym Partner's a Monkey, only appearing in the episode "The Two Jakes".
Just like their original counterparts, A Unit was voiced by Nika Fitterman, and J Unit was voiced by Tom Kenny.
Adam and Jake got sent to detention. Jake had a mirror, which he used to clone himself. When Adam asked him how he got ahold of this, Jake's answer was a simple "I know a guy.", as to be expected from him. Jake lent Adam a helping hand, by making a clone of him too, so that they could both do their detentions, while they lounged around in their lockers. In order to make Adam's clone a convincing replacement, Jake had to speed up his aging process, so that he would take on the form of a 12 year old. Adam and Jake's clones were titled "A Unit" and "J Unit".
A Unit and J Unit started off good at first, behaving the way their creators would in the situations, they would be put in, but when Adam and Jake overused them, A Unit and J Unit started to get a bit unstable. A Unit started teasing Principal Pixiefrog, getting himself in a lot of trouble. The two of them both tormented Slips, Windsor, Lupe, and Ingrid, giving Adam and Jake a bad reputation in front of their own friends.
Adam and Jake decided it was time for them to stop their clones, but their clones became too powerful. A Unit and J Unit started growing and turning into teenagers. Jake noted that because he sped up their growth process when creating them, they're going to continue aging at this rate.
As teenagers, A Unit and J Unit stole Principal Pixiefrog's motorscooter and started driving around on it, but this time, Pixiefrog spotted them in the same room as their originals, leading him to the conclusion that Adam and Jake had clones. Principal Pixiefrog got Nurse Gazelle to try and kidnap the clones and take them away, but she couldn't tell which ones were the clones and which ones were the originals. At this point, A Unit and J Unit had become young adults and it was clear which ones were the clones. Unfortunately, Nurse Gazelle's undeveloped soy bean-sized brain could not tell the difference.
A Unit and J Unit told Nurse Gazelle that Adam and Jake were the clones and she believed it. Nurse Gazelle captured Adam and Jake, while their clones ran off, getting away, scott free with their crimes. However, when they did, the two clones aged into senior citizens, making them extremely rickety and decrepit, not only throwing a hurdle at their getaway, but also getting Nurse Gazelle and Principal Pixiefrog to figure out that they were the real clones, settling the confusion once and for all.
However, the problem was not yet completely solved, as Adam and Jake still had to pay their dues, for creating clones to get out of detention. So, as punishment, they had to wash Principal Pixiefrog's car, while the clones watched. A Unit and J Unit basked in the sun, living out the last few minutes of their lives, mocking and teasing their creators. Given the rapidness and quick pace of their aging, it can be safely said that A Unit and J Unit died, shortly after the episode ended.