Meekrob

The Meekrob are a species made of 'pure energy' from the Invader Zim Universe and sworn enemies of the Irken Empire.

When they appear to Dib they quickly transform into giant flying shoes, claiming that their real appearance is impossible for the human brain to comprehend. However, their true appearance is clearly visible before the transformation and Dib tells them he had no problem comprehending it.

Behind the scenes
The only known appearance of the Meekrob was later revealed as being only an illusion created by Zim; therefore their status as a real species within the series' universe remains disputed.

Appearances

 * Invader Zim - "Dib's Wonderful Life of Doom"