aliens are already dead. Obviously, aliens should be about the classic sci-fi movie and not about aliens. Why are we even talking about aliens? Surely a conversation specifically about aliens would be off topic here? Oh... that tag has already been removed.
Can we also get rid of the zombies and vampires tags as well? I suspect that the bulk of these are going to be used where the genre tag horror is applicable, and the rest of the time they're going to be used on identification questions, rather than just being stated in the body of the question.