Micro Lad
Micro Lad might refer to one of two characters from different incarnations of the Legion of Super-Heroes comic book, published by DC Comics.
Lalo Muldron
Original and current continuity
In original Legion continuity, Micro Lad was Lalo Muldron from Shrinking Violet's homeworld of Imsk. He first appeared as part of a team of Legion rejects, and went on to lead the Imsk Liberation Front and join the Legion of Super-Villains (LSV).
In the post-Infinite-Crisis return of the original Legion, Micro Lad was murdered by Akka, one of Saturn Queen's recruits to a new iteration of the LSV.
This version of Micro Lad was originally part of the pre-Zero Hour DC Universe but is now known also to be part of the main continuity/main Earth in the current DC Multiverse.
Reboot Legion
In post-Zero Hour continuity, the character used the name Micro and again failed to join the Legion.
This version of Muldron was originally part of the post-Zero Hour DC Universe, but is now known to live on a parallel earth of the DC Multiverse.
Gim Allon (Threeboot Legion)
The "threeboot" version of Legionnaire Gim Allon prefers this name, as he comes from a race of giants and has the ability to shrink to normal human size. However, he is generally known as Colossal Boy.
This version of Gim Allon lives on a parallel earth (Earth-Prime) of the DC Multiverse.