AboutBasil Karlo began as an ordinary young man who desperately sought attention and differentiate himself from others. To this end he had tried to learn what it is about other people that makes them stand out, and then looked to becoming an actor. For several years, Karlo worked hard in acting but was told by a casting director that he wasn't good enough and that would garner a leading role. Unhappily, Karlo turned to the crime boss, The Penguin, for help. The Penguin offered Basil a hunk of clay which he claimed was the source of power for a tribe of Navajo skinwalkers in exchange for Karlo's services. Basil took the clay home and even as he examined it, the substance leaped up and into his body, entering his blood-stream and rewriting the fabric of his body. Transforming, he found that he could make his face mirror the world around him.
With this shape-changing ability, Karlo was able to achieve success in his acting career. As he got better in his acting, the clay inside him evolved as well. He gained the new ability to copy the DNA of anyone he touched and file it away in his memory, to be retrieved at any time. Outside of his acting, Karlo was employed by The Penguin according to their deal and participated in many of the criminal's schemes. This was something which Karlo was initially loathed to do but eventually grew to embrace. The actor lost sight of who he really was, until becoming nothing more than a mass of violence and rage. The more he lost control of his anger, the harder it was to hold his shape. Before long, Karlo's temper destroyed his career after he assaulted a director who berated him for ad-libbing on set. With no one willing to hire him and thus becoming a "nobody," Karlo became fully committed to a life of crime as "Clayface".