Board Thread:Theories and Speculation/@comment-26139703-20171205031143/@comment-33156027-20171205172255

Otsutsuki are extraterrestrial from other planet or even universe and Kaguya was one of them, so they didn't pop out of nowhere. We don't know how many are there. Momoshiki and Kinshiki for sure were not the last one we see in Naruto.