Let me introduce you to an alien world. This isn't my worldbuilding project, but I heard about it one day when I was browsing the web and wanted to share it because I love the creativity in it. External links about it will be at the bottom of the text.
This world has it's life underwater. Nothing there even resembles anything that you'd see if you went out for a walk, regardless of where on our earth you're reading this from. Most of the alien lifeforms on this world are so small that you could pick them up in your hand. Or maybe their world is really big?
Characteristics that you're used to seeing are combined in completely new ways. For example, there's one creature that has 5 eyes on stalks and a trunk with a claw to grab things with on the end. Its mouth is under it's head, so it can grab food and move it into its mouth. On its sides it has flaps that overlap each other and work a bit like fins to move through the water. Their body is quite narrow compared to how long their flaps are. They can be quite cute in their weird way. People who know more about this project than I do are debating if they would have compound eyes or not. Personally I think that compound eyes would suit them quite well, but for now I'm waiting for an update about their eyes.
There's another creature that essentially looks like a stick with spikes and 20 legs. The spikes stick out from its back in pairs. Unless you look really closely, it's gonna be difficult to tell which end of it is the front and which is the back. When threatened it can curl up into a circle with the spikes sticking out in all directions.
There are several creatures similar to the first one I described, except with 2 eyes and 2 grabbers instead of the trunk. These are usually bigger than the rest of these alien animals, with one in particular sometimes getting half a meter long. The apex predator is one of these, but it has close cousins that are filter feeders.
Something I only found out when researching for writing this to make sure I have up to date information about the worldbuilding is that another cousin in this family have a spherical shell on their back, covering much of the body. Some of them prefer to walk on the seafloor instead of using flaps to paddle around.
One of the most diverse groups of animals crawl around on the seafloor. They come in many variations, but are often ellipse shaped when you look down on them and have a hard shell. They're almost flat compared to how long and wide they are. They have many tiny legs. Their heads can look very different. Some have a plain flat half circle, some have long backwards pointing spines coming out from it. These have become a fan favorite, and I can see why. They're so diverse that regardless of what you like, there's something for you. I especially find the ones with long spines to be beautiful.
There are also animals that stick to the ground in one place and filter feed, acting almost like plant. These come in all shapes and sizes.
Up in the water, there are some animals that look a bit like semi-transparent hot air balloons without the basket. They're beautiful to look at as they float by.
These are just some of the alien creatures on this world. There are so many things you can do with this worldbuilding. I'd love to play a video game that's set here. Or watch a movie about it.
The best part is that there's no copyright on it that's stopping anyone from doing something with it. Here's a good jumping off point if you want to read more.
