The general assumption when dealing with aliens is that they are either monstrous killing machines that have no intergalactic technology (the kind that hitch rides on meteors or you meet when you visit an uncharted planet) or they are highly advanced entities beyond our understanding. Yet we always manage to defeat them. Because we are awesome.
However we should consider that the alien killing machine, when encountered in its own environment, is just a normal animal native to that world. Imagine you are a Grey and you land in the African savanna and meet some lions. Holy space crap! They have giant teeth and claws! They move at blinding speeds and cannot be reasoned with! Get to the saucer! Get to the saucer!
These definitely aren't the complacent mooing Terrans we are accustomed to dealing with.
That's what it is like to meet the monster aliens. They are the roaches, lions, deer, cows, platypuses and so on of their worlds.
Now the second type, being the highly advanced type, are probably like us. By that I mean that any truly advanced civilization will have a staggering variety of personalities present in its population.
One of the big failings of science fiction is the idea of homogeneity among all beings save Earthlings. All Vulcans are logical. All Klingons are proud warriors. And so on. From a literary perspective this is fine in the short run as these are merely allegories but in long term cases, such as a long running series or series of novels (and comic books) we have to explore and accept the notion that any advanced species with civilization and culture will have its criminals, its aberrant members, its greedy plunderers, its hippies, its politicans and its working Joes. Just like us.
Captain, what's that on the screen?
|"Just out for a little ride, I take it? I'm going to need to see your license to operate a starship and your cargo manifest."|
Standard Type 1: Grey but this one is green. We should not confuse it with the saurian breeds for this is definitely not of that lizard variety. Indeed these are the guys from Mars that left Mars long ago after an unfortunate incident involving an atomic reactor, two Martian dolphins and a cotton candy machine. Fleeing from Mars they determined that no other sentient species should ever have to suffer a similar fate. Rather than go on an anti-nuke crusade or send nanobots to planets to try to get them to recycle the Race Formerly Known As Martians decided to take more practical steps. There are few problems that a smart suit and a Flenobian Death Ray won't solve in short order.
Assessment: The RFKAM are-
I beg your pardon-
Begging will do you no good. You do not assess. You have not the qualifications to assess. We assess. Since the day when we shed our Corinthian helmets and pteruges we have been as far beyond your race as you claim to be beyond your Earth canines. Your presence in this sector is not authorized by the Intergalactic Enforcement Council Code 11789321998933432 Zeta-
Intra-Galactic. Let's be honest. The galaxy is big and so far my investigations have not gotten out of it. You Riffkam types can't possibly have left the galactic boundaries yourselves and even if you have this council has no authority outside of it. You have no member systems outside of the Milky Way.
Shut up, Earthbeing. Turn this ship around and get the Spacehell out of here before I run you all in for resisting a Galactic Peace Officer.
Next topic there, Space Ace.
Well, you heard the, um...man? Tune in next time for more helpful information.