I was a bit confused on this tag at first. There appears to be a manga series called "Yani Neko" by Nyannyan Factory (with this being their Twitter account). However it was an artist tag with an entry that looks like a second or third party account that posts about the series (I'm unclear if it's official, as it does look like the author has retweeted stuff from it). It doesn't look like the stuff sourced from it was all by the same artist, though. So I changed it to a copyright tag as it looks like it should be. Making a thread to note to change, and in case anyone knows the actual artists of the posts or what the situation is with that account (it seems like some posts are just from the actual manga).