Space Monsters? Help Please!

Im rly suprised no one has brpught this up before but would it be possible to mod in space monsters? I have had some sucess modding some simple things like adding new ship and creating new abilities, but I don't rly know how to do this the way i want to. I know how to create them and add them to planets at the start but would it be possible to make them  attack planets like pirates or like rebels from that TEC ability. If so could someone please help me, I have looked at the code that controls pirates and rebels and it simply confuses me.... This game would be so much better with giant space jellyfish, crystal organisms, and solar dragons randomly spawning and eating ships!

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