Superman's Pal, Jimmy Olsen #105

Story 2: "The World of 1,000 Olsens! Part 1]"

Jimmy is transported to an asteroid populated by a population that looks exactly like him, including some in the forms of his earlier transformations like Giant Turtle Man and Elastic Lad. But Jimmy is surprised to find himself suddenly thrown into jail by his lookalikes.

Story 10: "The World of 1,000 Olsens!] Part II: Jimmy against the Olsens!"

Jimmy escapes jail and discovers that the duplicate Olsens are androids created by the villain Tempus to help him move the asteroid out of orbit so it will collide with Earth! But with the help of some of his duplicates, Jimmy puts an end to Tempus' plans.