Here's an image I came across on pixiv of conjoinment/siamese twins that wasn't even tagged as such (and you can't add those tags either since it's already been tagged with the maximum amount of tags).

Image resaved as a PNG (from the original JPEG) because the file size was actually smaller that way (more than two time smaller in fact).

source: https://www.pixiv.net/member_illust.php?mode=medium&illust_id=44740005