demons are what they are. They are liars and cheaters but that has more to do with their own choices than it has to do with their “nature”. looks range because the devil’s face is everchanging. (unsaid is the fact that this is because the Lord loves drag and makeup really is temporary surgery. but we will keep clear of the subject lest people get silly ideas like oppression of gender expression in the name of religion, to make up an unreal example.) everyone who has written a book on financing advice against hiring demons, but really the only people who listen to those pigs are the even fatter pigs, so do not even worry about it.
angels are not saviours. They range from cultish purists to lost dead souls. Most are not concerned with the current plane of existence. They are in a sense similar to demons, both care very little of morals, but while demons are conmen and manipulators, angels hide behind the pretense of higher existence. But in their core both are less they pretend to be. angels have wings but not always, eyes are common but some choose to scoop theirs out (old fashion trends really were crazy) some are made of light and some leak blood. Really, it all depends on your own beliefs. Hiring an angel can be a pain as electronics burn and catch flame five times out of ten, but godschildren do honest work and are great for company image.
Is that crow a spy? probably not, but your aunt sure thinks those feral creatures are up to something. Usually it is easy to tell the differences between a feral creature and one deserving of workplace benefits by size. Is the owl as tall as you? then it probably is a guy named Pete. Some are exceptions, and some are just into odd hobbies but really if it looks like a duck and acts like a duck, it probably is a duck except when it is a pervert stalking you, or however that saying goes.