What aliens might look like is an interesting and difficult question to answer. Because we have not yet found any conclusive evidence of extraterrestrial life, we can only imagine the possible shape of extraterrestrials based on some assumptions and speculations. However, we can consider this in the following ways:
Chemical basis of aliens: We know that life on Earth is based on the element carbon, because the element carbon has a strong chemical activity and binding ability to form a variety of complex organic molecules. However, this does not mean that extraterrestrial life must also be carbon-based, and perhaps other elements such as silicon, sulfur, phosphorus, etc., can also form the basis of life in other environments and conditions. This would result in extraterrestrial life structurally and functionally very different from life on Earth.
The evolutionary history of aliens: We know that life on Earth has evolved over billions of years, from the simplest single-celled organisms to the most complex multicellular organisms, from aquatic to terrestrial, from invertebrates to vertebrates, from cold-blooded to warm-blooded, from unconscious to sentient, from unintelligent to intelligent. This process is influenced by many factors, such as the rotation of the earth, revolution, orbit, inclination, climate, topography, disasters, competition, cooperation, and so on. And the evolutionary history of extraterrestrial life may be completely different from the evolutionary history of life on Earth, perhaps shorter, perhaps longer, perhaps more stable, perhaps more turbulent, perhaps more diverse, perhaps more singular. As a result, the form and abilities of extraterrestrial life are very different from those of life on Earth.
Alien living environment: We know that life on Earth has adapted to a variety of living environments, such as temperature, humidity, light, oxygen, pressure, gravity, magnetic field, radiation, and so on. And the living environment of extraterrestrial life may be completely different from that of life on Earth, maybe hotter, maybe colder, maybe drier, maybe wetter, maybe darker, maybe brighter, maybe lower, maybe higher, maybe lighter, maybe heavier, maybe weaker, maybe stronger, maybe more, maybe less. This results in extraterrestrial life that is very different in appearance and characteristics from life on Earth.
To sum up, we can say that what aliens might look like is a question that has no definitive answer as it depends on a lot of uncertain factors. However, we can speculate on some of the characteristics that aliens may possess based on some general principles, such as:
Aliens may have some form of senses that they use to perceive their surroundings, such as sight, hearing, smell, touch, taste, and so on. These senses may be similar to the senses of life on earth, or they may be different from the senses of life on earth, such as electromagnetic induction, thermal induction, chemical induction, and so on.
Aliens may have some form of appendage that they use to manipulate objects around them, such as hands, feet, claws, tentacles, flagella, flaghairs, and so on. These appendages may be similar to or different from those of life on Earth, such as magnetism, electrostatics, suction cups, barbs, and so on.
Aliens may have some form of communication that they use to communicate with their own kind or other creatures, such as words, sounds, movements, expressions, colors, smells, signals, and so on. These communications may be similar to or different from those of life on Earth, such as telepathy, radio waves, light waves, chemicals, and so on.
Of course, these are just some possibilities, and they don't mean that aliens will necessarily have these characteristics, nor does it mean that aliens will only have these characteristics. Aliens may have other traits that we can't imagine, or they may not have some that we think are necessary. The possibilities of aliens are endless, and it's only when we actually encounter them that we know what they really look like.