AP was originally known as Captain Atomic, Mega City's famous hero, who for reasons unknown was transformed into a puppet none other than Mookie (aka Segeant Sub Atomic and Nuclear Boy), who is his former yet washed up sidekick who turned on him caused by Jealously from not getting any appreciation of any efforts although nonetheless of his actions of wanting to be above Captain Atomic in heroism.
He had other association with certain people who makes up with creating merchandise for him, as the relationships between them are rather strained as Captain Atomic seem less satified or more angered of anything that doesn't suit his expectations, for example, when Mr. Inkwood created a comic for him, all he complained about not adding dimples in the right way or so and when the time when the Toymaker created some type of toy which had it as a ballerina which had angered Captain Atomic, causing him to destory whatever left in the labs.
While unpowered, AP looks like a dull blue sock puppet with a light gray chin. He has yellow fabric details on top of his head resembling Captain Atomic's mask accessories. His eyes are two large yellow buttons that are attached via yellow string. He has a patch with a red letter A and a white oval embroidered into his chest. His arms have light gray fabric resembling bare skin, as well as red fabric representing his gloves. His lower body has two red strips running across it. There are visible stitches in various parts of his body, as well as a red cape attached to his back.
As part of Atomic Puppet, AP is considerably bigger and more well refined looking. The dull blue on his body is replaced by a more vibrant shade and the light gray is replaced by a periwinkle color. The decorations in his head become much more detailed, and the button eyes are replaced by regular ones. His cape grows larger and is now adorned by two golden buttons. His arms get buffer and his gloves have a slight cut in them. The patch on his chest develops into the official Atomic Puppet logo, and the red stripes now resemble red overshorts held in place by a golden belt.
While as Captain Atomic, He appear muscular and does not wear boots like Joey when powered up, but rather had shoes with cuffs.
AP, at first glance, has all the traits of a comic book superhero, he's heroic, dashing, and has a strong sense of duty. However, due to living his entire human life with superpowers, he developed a big ego, and often feels to be above to the world around him. AP is oftentimes very full of himself, and thus finds it hard to swallow his pride and recognize his mistakes when the time comes for it. Just like Mookie, he enjoys public attention and will try to prove himself to be the hero Mega City deserves.
Despite his faults, AP is genuinely heroic and is not one to betray someone close to him.
AP, for the most part, doesn't care much about being turned into a puppet anymore, however, in Justice Alliance, he's shown to be self-conscious about his condition among other superheroes. He doesn't seem to mind leaving behind his days as Captain Atomic in favor of the new superhero Joey and him form.