I like to imagine life forms with little or no humanoid characteristics. This is harder than it sounds. As soon as you put something like a dot or whiskers, it starts looking like an earthly creature. In fact there is probably nothing completely alien-looking on our planet, since nature has already come up with any possible design for life over a billion years or so.
I started with a simple circle or oval, then added a band of whiskers around it, and added eyespots on its body, and there I already had protozoa. These tiny creatures, more accurately called "protists," live in water or moist soil. Their variety is endless and their numbers countless. In this drawing I've portrayed at least five varieties of (imaginary) protozoan.
In my teen years, I kept protozoa as "pets," that is, in a sample of swamp water in my room. I grew up in a forested environment with many swamps or wetlands which could not be built on. These areas were my playground and when we covered the protozoa in high school I got to keep my very own live collection. I had a little microscope, produced in Japan by an entity called "Micronta," which had glass slides to put your drop of pond water on. There was, as the cliche said, a world of life in that one little drop. I was able to identify a few species, like Paramecia and amoebas and rotifers, all of which were tiny specks to the naked eye but lively mini-beasts in the microscope's view. I drew pictures of some of them, though I don't know where those drawings are now.
Unfortunately, to observe these creatures I had to destroy them, since I couldn't return them all to the water jar or the pond. It's possible that some of them might even be harmful to humans, though my collection gave me no trouble. When their life cycle was over in the jar, I poured the water out into the dirt in the backyard and threw out the jar. I may have studied micro-life as a high schooler, but I never followed it up by becoming some kind of scientist or micro-naturalist.