We may know and think of Plastic Man as a character straight out of DC Comics, but the company can't claim creation rights. That honor goes to the now defunct publisher, Quality Comics. Back in 1941, Quality Comics' artist and writer Jack Cole came up with Plastic Man for Police Comics #1. The company continued to publish what became one of their most popular characters for 15 years before DC Comics ever entered into the picture, buying the rights to the hero.
Plastic Man was created all the way back in 1941 and he was an incredibly popular character for more than two decades before Reed Richards was ever created. The Fantastic Four didn't debut until 1961, 20 years after Police Comics #1, which featured the debut of Plastic Man. Granted, DC and Marvel's library of characters tend to match one another, but Plastic Man has longevity over Mister Fantastic in this case.
Back in the 1940s, it wasn't uncommon to pair off a superhero with a sidekick. Batman had Robin and Plastic Man had a comedy sidekick who went by the name Woozy Winks. He is almost always depicted wearing green pants, a black polka-dotted green shirt, bowtie and hat. He was a big part of the earlier stories, but rarely made appearances in the books through to the modern age. He has appeared in cartoons, but has yet to make much of an appearance in modern comics.
Back in 1979, when DC's Super Friends was smashing television ratings for ABC, the network released The Plastic Man Comedy/Adventure Show to air directly after Super Friends. The show was an amazing success and ran until 1981. The series was broken into separate vignettes all related to the hero. These included Plastic Man, Baby Plas, Plastic Family, Mighty Man and Yukk, Fangface and Fangpuss and Rickety Rocket.
Plastic Man was created around the time the plastics industry was getting started, which may have helped mold the character into one who could take any shape... like plastic. Regardless of the reasons for his ability, Plastic Man has shown a remarkable affinity to transform himself into anything. He may be one of the silliest characters in the DC Universe, but he may also be one of the most powerful. Over the course of his publication, Plastic Man has been shown to be immortal and there doesn't appear to be any way to destroy him for good. He has been frozen and shattered numerous times, but he is able to reform himself just like the T-1000 in Terminator 2. Additionally, he doesn't age. In the "Obsidian Age" storyline, he was found to have had his molecules scattered across the floor of the Atlantic Ocean, but was able to eventually recombine after 3,000 years.