Any tips for creating an extraterrestrial ecosystem via randomized combinations of animals?

[GodzillaLouise]

The title’s pretty self-explanatory, but I’ve come up with a process inspired by Cas3yart’s many “Random Aliens” on YouTube Shorts and plan to make a small number of extraterrestrial genera for it. Cas3yart’s process is that he basically takes 3 books, opens each one up to a random page, and then draws an animal based on the evolutionary science and combination of whatever those 3 pages were. If anyone needs a better explanation, I’ve made a collection of links to them, so that it’s easier to understand.
https://docs.google.com/document/d/1W26 ... MDm4M/edit

In my version of the process, I have 7 lists: 6 lists of lifeforms (2 prehistoric animal lists, 2 lists of modern lifeforms, and 2 of mythological / cryptozoological creatures) and a 7th list of ecosystems. I then roll an irregular-sided dice on calculator.net to randomly generate the inspirations from each list. I then modify it slightly by taking out 1 of the mythological creatures from the list, creating the final version of the inspiration for the extraterrestrial genus.

So far, I’ve generated 15 extraterrestrial genera via this process, but none of them have been given anything definitive yet. The reason I’m asking for tips on what to do is because I’m not particularly well versed in biology, so I don’t know where to begin with this project.

Here’s the first 15 extraterrestrial genera I’ve generated via this process: https://docs.google.com/document/d/1Uei ... ZQWfk/edit I’m sending this because I want more than just tips on how to go about this project in general: I also want help coming up with ideas for the first 5 genera on the list, so that I can get started easier.

[Visions1]

Have you considered constructing food pyramids/webs, or visualizing what the biomes would be like?
Also, I notice a lot of these are animals. What are the flora like?
Hammering out the edges is a great way to get a fuller picture.