An alternate identity employed by Jimmy Olsen on those occasions when, after drinking a special "elastic serum" which temporarily endows him with the extraordinary ability to stretch his body as though it were an endlessly stretchable elastic band, he participates in the adventures of the Legion of Super-Heroes, of which he is an honorary member (S No. 172, Oct 1964: pts. I-III—"The New Superman!"; "Clark Kent—Former Superman!"; "The Struggle of the Two Supermen!"; and others). (TGSB)
In May 1986, Elastic Lad joins the Elastic Four (DCCP No. 93: "That's the Way the Heroes Bounce!").