I think the trope "rubber forehead aliens" is broader than just that literally, but is referring to aliens who might as well just be humans. Daleks are still "r

I think the trope "rubber forehead aliens" is broader than just that literally, but is referring to aliens who might as well just be humans. Daleks are still "rubber forehead aliens" in that they aren't really that alien psychologically -- they are basically just metaphorical Space Nazis who think they are superior to everyone else and who want to rule the universe. And Tribbles don't really count at all because they are just props and not characters. A true non rubber forehead alien would be the squid-like things from Arrival -- not only alien in shape but alien in mind.