And The Most Inconsistent Looking Aliens (outside of the whole Star Trek thing)...

..Marvel Comics and the Chitauri!

 

 Marvel Comics

Below from The Ultimate Avengers Animated movies

 And their big movie break in Avengers Assemble! (the movie and NOT any other thing titled "Avengers Assemble")

At least those little Grey bastards are consistent in appearance -apart from when they mind manipulate- but then they ARE real, right?

RIGHT???