This is the animated version of Clayface from "Batman: The Animated Series (1992–1995)" and "The New Batman Adventures (1997–1999)".
Matt Hagen was a well-known movie actor who after being badly disfigured in an automobile accident, became addicted to a "miracle product" RenuYou which could restore Hagen's features within minutes as compared to years of plastic surgery.
When he was overdosed with the untested toxic chemical, it transformed him into a hideous man of clay. Hagen soon realized that his new cellular structure allowed him to change his shape and appearance. He could form anything he wanted just by thinking it. As a living shape-shifter, he became the evil Clayface.
There are at least three versions of this 5-inch Clayface figure from the animated Batman series. The original was brown with the silver slashing claw hand and launching spiked ball. For the "Rogues Gallery" version, Clayface was repainted in gray.
This particular version I picked up from the flea market (apparently this is a "Toys R Us" exclusive CLAYFACE with break-apart safe and TNT) and what caught my attention other than the different color scheme was the left fist hand instead of the launching spiked ball.
In the Marvel universe, Clayface's equivalent would be Sandman, a shapeshifter endowed through an accident with the ability to turn himself into sand.