Talk:W. D. Gaster/@comment-31264199-20170209043937

This Tweet from Toby showing early concepts for Papyrus does lend some credence to the theory that Gaster is related to Sans & Papyrus:

https://twitter.com/tobyfox/status/818211590696800258

Obviously the blacked out part on the right isn't necessarily a Gaster reference, but it does imply that either early on Sans & Papyrus were supposed to have another family member but that character got scrapped, or the character is present but Toby wants to keep them a secret for some reason.