Clayface
Clayface
Name of a number of villains who adopt methods of transforming themselves or causing transformations, including the original Clayface, Basil Karlo, as well as Matt Hagen and later, Preston Payne.
Matt Hagen is a man who uses a weird protoplasm to transform his appearance after taking on a clay form (first appearance: Detective Comics No. 298, Dec 1961: "The Challenge of Clay-Face"). Traditionally an enemy of Batman, Clayface also faces Superman after morphing into his double, complete with super-powers. Superman (along with Batman and Robin) is able to defeat Clayface with Red Kryptonite, causing the mutating menace to lose control over his shape-shifting abilities (WF No. 140, Mar 1964: "The Clayface Superman!").
(see also, WF No. 144, Sep 1964 "The 1,001 Tricks of Clayface and Brainiac!" -- a story that involves Jimmy Olsen teaming with Batman and Robin teaming with Superman to defeat the combination of Clayface and Brainiac)