Err has an appearance similar to a character from a very early home video game system. He is extremely pixelated, to the point of being an unrecognizable object. Err is pink and blue, and he speaks with a very high pitched voice. He has a permanent scowl.
Like Ignignokt, Err is mischievous to the highest degree. Err's pranks don't just include crank calls and graffiti, but also mindless destruction and convincing others, usually Meatwad, to do bad things like shoplifting, swearing, and drug abuse. Err often does these bad things himself. He often steals things, and he has mentioned sending "illegal substances up the river."
Err almost always blindly follow Ignignokt's plans to mess with the Aqua Teens. However, in some instances he seems to be doing this against his better judgement. For example, Err said he was aware that the check that Ignignokt was trying to cash was actually a bill in "Remooned.
- Mayhem of the Mooninites
- Revenge of the Mooninites
- Super Computer
- The Last One
- Moon Master
- Deleted Scenes
- 2-And-a-Half-Star Wars Out Of Five
- Allen Part Two
- Freedom Cobra (censor)
- Jumpy George
- The Granite Family
- Spacecataz (Season 3 cold openings)
- Aqua Teen Hunger Force Colon Movie Film for Theaters
- Aqua Teen Hunger Force Zombie Ninja Pro-Am (video game)
- According to the DVD commentary for "Mayhem of the Mooninites," Dave Willis and Matt Maiellaro drew inspiration for The Mooninites from an urban legend. They had heard that there were so many returned copies of "E.T. the Extra Terrestrial" for Atari 2600 that the publishers buried them in the desert. Err and Ignignokt were originally intended to be the ghosts of that video game burial.
- If Err was intended to be a sprite from a fictitious video game, then his appearance is illogical. Err is composed of pixels of different sizes. This would be not be possible for Atari 2600 games.
- In certain episodes, such as "The Granite Family," Err's voice sounds different than it normally does. Matt Maiellaro, the voice of Err, has stated that this is due to his having a cold.