Gim Allon, also known as Colossal Boy, but prefers "Micro-Lad".

Powers and abilities

As Colossal Boy or Leviathan, Gim Allon can increase his size into many times normal height, with strength proportionate in mass. He additionally possesses expertise in law enforcement. In the 2004 reboot of the Legion of Super-Heroes, he is giant-sized normally and can shrink down to six feet tall.

Equipment

As a member of the Legion of Super-Heroes, Gim Allon is provided a Legion Flight Ring, which allows him to fly and survive in the vacuum of space and other dangerous environments. Brainiac 5 modified his ring so it would enlarge with him, thus supporting the additional mass.

The New Golden Age

In the pages of "The New Golden Age", Colossal Boy is among the Legion of Super-Heroes members that arrive in the present and confront the Justice Society of America over their decision to add Legionnaire (a younger version of Mordru wanting to avoid the path of evil) to their ranks.

2004 reboot - 2004 reboot

In the 2004 relaunch, Gim Allon is a member of a race of giants created by Bizarro Brainiac 200 years prior to the start of the 31st century. Allon considers his superpower to be the ability to shrink to six feet tall and prefers the code name Micro Lad. Still, all Legionnaires, as well as the public in general, know him as Colossal Boy. He often affects a bemused manner with his comrades, enjoying his time spent with "little people". Gim is often both the first and last Legionnaire in a fight, as his size grants him first strike ability as well as serving useful in cleanup operations.

1990's - Gim Allon was known as Leviathan and was from Mars instead of Earth. He was still human, as Mars had been colonized by humans in this continuity. Like his previous counterpart, he was a Science Police officer who was given his powers after being grazed by a meteorite.

He was the first official leader of the team, but he resigned after one mission, following the death of the first Kid Quantum and realizing that Cosmic Boy was more suited to the role. Cosmic Boy persuaded him to retain some leadership as deputy.

Allon then became ensconced in a love triangle. While he nursed a crush on Kinetix, Shrinking Violet nursed a crush on him. This ended in tragedy when the Emerald Empress' Emerald Eye of Ekron, on orders from Violet to give each member of the team their heart's desire, caused him to die in battle with Doctor Regulus, fulfilling his wish to have a heroic death. He also passed along his ability to grow to tremendous size to Violet.