Vietnam War Veteran

The Vietnam War Veteran (real name unknown) is a spy hired by the government to learn about the Nathan's Classes school. He also claims to have been in the army and fought in the Vietnam War, but this hasn't been confirmed. However, he did take part in the colonization of planet A-Lee-N, and it is possible that he believed it was the Vietnam War.

Overview
The Vietnam War Veteran is seen on planet A-Lee-N during its colonization. At some point, he returns to Earth.

A long time afterwards, the Vietnam War Veteran joined the class at the beginning of Season 4, along with several other new students. He rubbed the class the wrong way with annoying comments, but either didn't care or didn't notice, as he didn't stop. Eventually this pushed Jack over the line and Jack tried to fight him, however Lightbulb Television stepped in and changed into Sir Geoffrey. After Sir Geoffrey beat up and killed Jack, the Vietnam War Veteran killed Sir Geoffrey with one punch and explained that he and Sir Geoffrey used to fight side-by-side together in the Vietnam War, but had a falling out and never spoke to each other again. Later, Riley accuses the Vietnam War Veteran of being a government spy, which the Vietnam War Veteran admits to it being true. The whole class starts yelling insults and accusations, and Peter pulls out a revolver and promptly shoots the Vietnam War Veteran in the head. Later, he arrives in the Land of Box and is beamed up to Earth by Box. It is unknown what happens to him next.

It Only Gets Weirder
In It Only Gets Weirder, the Vietnam War Veteran was a new student joining the class, along with Pat, Lightbulb Television, Bones, Mil, Santa Claus, and Mrs. Claus. The Vietnam War Veteran punched Santa Claus after he got confused because of a helicopter, and talked about being in the army. The class later went outside, and the Vietnam War Veteran responded to everything with how he did stuff when he was a kid, in the army, or in Vietnam. Jack gets annoyed by this and goes to fight the Vietnam War Veteran but accidentally bumps into Lightbulb Television, who turns into Sir Geoffrey and attacks Jack. Sir Geoffrey kills Jack, so the Vietnam War Veteran kills Sir Geoffrey with one punch and calls everyone idiots.

He's a Spy
In He's a Spy, Jack gets beamed back up to life by one of Box's yellow lasers and the Vietnam War Veteran comments how yellow lasers weren't invented when he was a kid. The Vietnam War Veteran then reveals that he and Sir Geoffrey used to fight side-by-side in Vietnam but Sir Geoffrey got mad when the Vietnam War Veteran killed a soldier and after a big fight they never saw each other again. Everyone goes inside for show-and-tell and the Vietnam War Veteran gets mad at Mil for being disrespectful. Riley thinks that the Vietnam War Veteran is a spy hired by the government, which the Vietnam War Veteran clarifies as true, and the whole class turns against him. Peter pulls out a gun and shoots the Vietnam War Veteran, killing him.

Everything Goes Wrong
In Everything Goes Wrong, the Vietnam War Veteran arrives in the Land of Box, and Box beams him up to Earth. He is not seen after that.

Gilfrek's Revenge
In Gilfrek's Revenge, young Vietnam War Veteran appears briefly during the colonization of planet A-Lee-N. As baby Gilfrek tries to escape, the Vietnam War Veteran sees him and comments about how he didn't know there were aliens in Vietnam. Gilfrek flies into outer space, leaving the Vietnam War Veteran behind. It is unknown how long the Vietnam War Veteran stays on A-Lee-N, but he most likely escaped back to Earth during the Gigabites' revolt led by Blaggabuh.