The Postal Dude is the main character of the controversial Postal series.

He appears in the Elliott goes to School series, and appears in episode 3 and 4, where kills Mr Person, then humilated by Brandom, following by flying off on a jetpack in episode 4, and then trying to steal a car in episode 3, failing and claiming that all cars are "props", followed by flying off on a jetpack once again.
Postal dude

The Postal Dude