Define Angry German Kid Meaning

1)

A fattish german boy who turned viral via youtube, it is undetermined whether he is an actor or not.

The Angry German Kid sit's in front of his computer playing Unreal Tournament and constantly yells abuse and smashes the shit out of his Keyboard in the process, he can't handle losing, he can't handle lag and he can't handle the game not loading.

In the end he goes insane, smashes his keyboard to hell, screams a few more times at the computer and then runs away with a whimpering sound going to have a cry like a little bitch.

Many youtube videos have been made with differant English subtitles to make it funny and fresh each time and even though it's just the same clip with differant sub titles it continues to be funny (as long as the person who makes it isn't a dickhead).

2)

Used to describe someone who loses their temper or rages at the computer or anything else for no reason.

A very loud, annoying, fat kid who likes to scream at his computer, smash his keyboard, and talk to himself when he's loading/playing/losing in Unreal Tournament

Some german kid mocking the boomer's idea that "video games make kids violent and affect their mental health".
He posted a video in which he was trying to boot up the computer to play unreal tournament, but the game was taking too long to start which caused the boy to lose his temper and start beating up his keyboard and yelling at the monitor, the video ended with him rage quitting after he lost the game, the boy yelled at the top of his lungs, took the keyboard and smashed it repeatedly causing it to break, all of this was just act to mock the boomer's perception of how their kids behave when playing video games, but unfortunately people who watched this video did not get the satire and mistook him for a kid who is mentally challenged, which nearly ruined his life.
This video became a popular meme around the mid to late 2000s internet, a lot of people made parodies of this and even fan-fictional animations.