Disambiguation: Matt Hagen, from Batman
First published in: 1961
Created by Bill Finger and Sheldon Moldoff.
First appearance in Detective Comics (DC, 1937 series) #298 (December 1961). He died in Crisis on Infinite Earths (DC, 1985 series) #12 (March 1986). Shown to be alive in Infinite Crisis (DC, 2005 series) #7 (June 2006).
The Infinite Frontier Matt Hagen first appeared in Batman - Knightwatch Batman Day Special Edition (DC, 2021 series) #1 (November 2021).
Link: https://en.wikipedia.org/wiki/Clayface#Matt_Hagen