I am writing a story that has clans, apprentices, warriors and stuff like that from Warriors by Erin Hunter, but it has different plot, characters, ex. Can I still write it and publish it?
I'm also writing about my characters in Zootopia can I write it and publish it as well?
The first one, I think so. If you're doing cats as well then you might have some trouble. You can definitely write, although publishing might be a problem.
For your Zootopia one, you have the same problem. If you're just taking the setting, then you can probably get away with it but get too close to the original and you get trouble.
But fear not! For the infinite wonders of the interwebs have provided a solution to such problems as these! Behold! fanfiction.net! If your stories get too close to the original inspiration, you can post it here as fanfiction. Yeah it's a rather dead site and you don't get paid or anything but at least you can put it on the internet. Probably better platforms somewhere. IDK if wattpad takes fanfiction but that would be a better choice if they do.
Depends on what you mean by the word "publish" but for these purposes, I'll assume as a book for the purposes of profit to yourself.
For your first question, Yes you can, so long as the Clans, Apprentices, and Warriors are not similar to the the ones featured in Warriors by Erin Hunter. Avoid similar names, similar customs, cultural values, and other identifying features where-ever possible.
For your second question, I'm assuming this is an original character who lives and/or works in the fictional setting of the 2016 film Zootopia. You cannot publish this per the assumed definition above.
Broadly speaking, Publish means releasing your story for the public to read and review. This is fine for both ventures. Fan fiction is not illegal to make/distribute under fair use guidelines. Since Disney owns all intellectual property rights to Zootopia, unless they specifically gives you permission, you may not use anything related to Zootopia (be it the titular city, that the characters you created are taking rookie training courses from Judy Hopps, or that your OC has a massive crush on Flash from the DMV) and make a profit off of it (and Mickey has powerful lawyers). If you aren't writing this to make money, but because you like telling a story, fear not, fan fiction generally falls in the catagory of fair use when it isn't making profit off of the copyright/trademark holder's own works and is transformitive in nature (adding new characters or building on the story premise are transformative).
