Prisoner #234026 is the original Killer Moth, his real name is unknown.
Further information: List of Batman Beyond characters#Terrific Trio
2-D Man is a villain in the Batman Beyond animated series. His powers are elasticity and the ability to be two dimensional, which means he has a square shaped body with virtually no curvature to his joints. Therefore his body has no depth to it and he resembles a thin piece of paper. His real name is Stewart Lowe and he is a member of the villainous group The Terrific Trio.