Idk about mods, but I think you could find the answer to that on discord
As for editing cats, open the game, go into settings and click the Open Data Directory button in the bottom left corner, then open the folder with the clan that you want to edit and look for the clan_cats.json file. There will be a loooooooooong list of all the cats you have and you'll be able to edit everything. Hope this helps :) (Btw, never done this before, so this might not work, but I'm assuming this is how you do it)