Colossal Boy

Gim Allon
Gim Allon as Leviathan. Art by Jeff Moy.
Publication information
Publisher	DC Comics
First appearance	Action Comics #267 (August 1960)
Created by	Jerry Siegel Jim Mooney
In-story information
Alter ego	Gim Allon
Species	Metahuman
Place of origin	Earth (31st century)
Team affiliations	Legion of Super-Heroes Science Police
Notable aliases	Leviathan, Micro Lad
Abilities	As Colossal Boy and Leviathan: Expand his body to giant size Superhuman strength and mass As Micro Lad: Shrink size of his body

Gim Allon, also known as Colossal Boy, Leviathan, and Micro Lad, is a fictional character in the 30th and 31st centuries of the DC Comics universe who has gone by a variety of superhero names over the past several decades, although originally (and most commonly) Colossal Boy. He is a member of the Legion of Super-Heroes. He first appeared in Action Comics #267 (August 1960). In the 1990s, the entirety of the Legion of Super-Heroes were changed in what was referred to as a "reboot" of those characters' continuity, including Allon. Later on, these superheroes were again restarted in what has been referred to as the "threeboot" of the Legion of Super-Heroes.

The character's name's similarity to the standard Israeli surname Allon led writer Paul Levitz in 1980 to identify the character as Jewish.

Gim Allon was mutated by a radioactive meteorite, gaining the superhuman ability to increase his size. His superhero codename became Colossal Boy. With his parents' blessing, he joined the Legion of Super-Heroes, becoming a member in good standing. He had an unreciprocated crush on fellow Legionnaire Shrinking Violet; this crush was only returned when Violet was replaced by a shapeshifting impostor, a Durlan named Yera. The two were married; when the deception was exposed, he discovered that he was still in love with Yera, and they remained married. For a time, Colossal Boy's mother Marte Allon was the President of Earth.

During the "Five Year Gap" following the Magic Wars, Gim joined the Science Police and ultimately never returned to the Legion. Earth fell under the covert control of the Dominators, and withdrew from the United Planets. A few years later, the members of the Dominators' highly classified Batch SW6 escaped captivity. Originally, Batch SW6 appeared to be a group of teenage Legionnaire clones, created from samples apparently taken just prior to Ferro Lad's death at the hands of the Sun-Eater. Later, they were revealed to be time-paradox duplicates, every bit as legitimate as their older counterparts. After Earth was destroyed in a disaster reminiscent of the destruction of Krypton over a millennium earlier, a few dozen surviving cities and their inhabitants reconstituted their world as New Earth. The SW6 Legionnaires remained, and their version of Colossal Boy assumed the code name Leviathan.