I have thought long and hard about what it would be like to be an alien. I am of the opinion that they would be so entirely unlike us that this thought experiment is much less effective than you might guess. We have access to the world through our senses and much of it is arbitrarily so. We see a certain range of the light spectrum, we hear a certain range of audio frequency, we touch, taste and smell according to reactions to our environment and our survival tendencies over many millenia.
An entity on another planet whom we might consider to be living would have to exist in harmony with an entirely different environment such that they might be as physically different from us as fungus is from a cocker spaniel.
It is not really that uniquely interesting to consider all of the different life-forms there might be on other planets. The diversity on Earth is astonishing enough. What is interesting is to consider how a so-called intelligent life form might look and move and act. Could we assign the act of thinking to any intelligent being? What essentially do we know about thinking so that we can definitely say that another life form thinks? How do these beings interact with each other? What of socialization? Individual identity? Is individuality something unique to our particular condition in our particular environment? Would these creatures be a collection of individual creatures or one single creature? Must intelligent beings be evolved to a state that possesses a sense of self?
Ask yourself what it is about being human that has brought us to where we are and how we are. You are left with certain aspects that we would call particularly human. These traits and tendencies are alien even to other life forms here on earth. Think of how much we would need to have in common with a being in order to communicate with it. Over 20 years ago we sent out an intergalactic message in a bottle on the spacecraft Voyager. How similar would we need to be with the recipients in order for them even to consider our message to be something of importance worth investigating? Could there exist an highly advanced being that never looks out above the surface of it's planet? Could they even see? If they could detect the existence of Voyager would they even care? What is it to care? Must an intelligent being necessarily be curious?