“They look incredibly hostile because they are an unknown” ...
What if the alien were a bacterium or a virus? You may already be facing them every day. Though some of these things are “known” to you, and have the most benign “look” you can imagine (bacteria in particular; they won’t make faces at you no matter what you try to do to them), any “hostility” in this case would be a projection of your own attitude toward the unknown thing.
If I met a dolphin while swimming – which species, except for television and movies is “unknown” to me – I think I would be intimidated by its power and familiarity with that environment in a way that I can never be, but I don’t think I’d feel that it was “hostile”. Same with any other fish. Even a shark that had clear designs on my leg – or even a taste of it – could not be considered “hostile”. It would only be attempting to satisfy its hunger and curiosity.
I recommend that you not apply for the position of human ambassador to alien races. Please.