Board Thread:Questions and Answers/@comment-203.87.139.71-20140223111326/@comment-29810559-20171027215712

It goes like this. Twins and triplets literally MEAN born on the same day! You can't be a twin or a triplet if you're not born on the exact same day. But can be a different minute or hour because that's the usual way and if not, they are cojoined twins, literally meaning their bodies are physically attached to one another. Some share the same body but have two different necks and heads, like Peri and Pearl Serpentine from the original Monster High franchise before the reboot.