>>58575308There is a fat booru called curveybooru, but I don't think it's that popular to where every single piece of fat art finds it's way there.
Pixiv is always an option to get fat from japs and it let's you filter AI.
I'll be honest though, most art I collect has just be accumulated across /d/ and other various 4chan boards, and if an artist catches my fancy I'll keep tabs on them and only then do I get content from the source.