The name bestowed, for want of a better one, on "a shapeless protoplasm" capable of assuming any form it pleases and of duplicating, down to the most minute detail, the characteristics of whatever being it has chosen to impersonate—which arrived in the twentieth century in February 1954, after having been banished from its own era—the year 40,000 A.D.—by a populace that had grown afraid of it. Temporarily stranded in the twentieth century, "the Thing" took on the from of various individuals—including Superman—as part of its elaborate scheme to steal the advanced technological compontents necessary for the construction of a "time machine," with which it intendeds to return to its own era and set up a dictatorship. Superman ultimately destroyed the creature (or so he believed), by luring it into the midst of a hydrogen-bomb explosion. "Whew! That H-bomb gave me a slight headache!" mused Superman. "But it finished my rival--completely! He couldn't adapt himself to an explosion of such magnitude!" (S No. 87/1: "The Thing from 40,000 A.D.!").
In January 1986, Superman discovered that the creature had in fact survived the hydrogen-bomb's explosion, and he teamed-up with the Omega Men to once again face the Thing. (DCCP No. 89/1: "Metropolis Wasn't Built in a Day... or Was It?")