LOTS of creatures here "look like us" :)
Earlier, LaeMi Qian wrote "Humanoid aliens? Again? ... What proportion of creatures on this planet resemble us physically?"
Completely skipping over the Roswell story here... but depending how you look at things, MANY creatures on Earth "resemble" humans (or us, them). For example, bilateral symmetry is pretty popular. A "face" is pretty common also (mouth, eyes, scent-detecting orifice...) Four limbs is a hot configuration also. (Mind you, most of us trot around on all of them at once...) Humans and zebras are actually very similar!
The "tube" design, where nutrition goes in the "front" end and waste exits from the "back" end is also a well-established approach.
Mind you, most vegetation and a lot of sea life don't fit the pattern. Indeed, we don't match well with starfish or carrots. However, neither of them are busy at work changing their environment. Making and launching space probes and such.
Snakes have a head, face, mouth, eyes, nose, ears... but lacking a way to reshape the world around them (and enough brains), they remain animals.
I don't know what an alien WOULD reasonably look like, but if the creature could not manipulate its environment, it's not likely they'd get into space at all!
If humans never made it, would a zebra have been the first Earth being on the Moon? Not likely, because with hoofs you do not build an industrial society.
I happen to suspect that whales and dolphins are VERY intelligent. But due to their physical "configuration" its not likely that THEY will be building space ships soon either.
So, while aliens that supposedly crashed on Earth would most likely NOT look like humans, they probably would look more like humans than starfish. Evolution-wise, you need to ask what is the benefit of radial, as opposed to bilateral symmetry. Many plants have radial symmetry. But they aren't building space ships either (at least, I haven't heard so).
An alien that is a "blob" is unlikely too: the same problem arises... how did they develop an industrial society? I could allow six legs rather than four, or something that normally uses all its limbs for moving around.
. . .
Hey everybody! Read some science fiction and get back to us. :)