Space Mutants

The Space Mutants are the titular antagonists of the video-game, Bart versus The Space Mutants - which has gained infamy due to a series of popular reviews and parodies on varied internet sites, most notably the Angry Videogame Nerd.

The Space Mutants themselves have never (to date) appeared in The Simpsons franchise outside the game, despite the game being inspired by the cult sci-fi movie "They Live" the aliens did not resemble the antagonists of any movie and were rather generic "space monsters".

The basic plot revolved around the Space Mutants trying to create a weapon using obscure sources of "fuel" which Bart destroyed via progressing across varied levels (as the Nerd famously quoted the plot made very little sense, sadly a common theme in early video-games).