There are listed worlds in the wiki, that's as far as summoning worlds are developed. Developing this summoning worlds needs both players and storytellers working hand in hand. It's a tough job, even if you've got a good idea, and even if the idea gets approved, creating an entire world is no cheesecake. Gossamer summarized all the problems that's forming a big formidable roadblock in front of my dreams of intergalactic space travel.
I have tried modding for people to jump them to another world, but alas, they either become disinterested or retire too soon. One of the best mizahar-themed threads in terms of space exploration is in Sahova, modded by Tarot and played with Vick, but they are not speedy writers, and are both busy people. I gnaw my fingernails as I wait for the movement of the plot of :
The Frontiersman.
As for summonable flora and fauna, I know there is at least one player trying to create her own world(s). Check the world development! You can contribute and peer review Jilitse's article. She is still working on it the last I heard. If you're interested (in creating your own world) you and your co-summoners will greatly benefit in the process.