Board Thread:General Discussion/@comment-4504826-20160516040951/@comment-27117057-20170209212616

What I have in mind is somewhat similar to the partnership theory mentioned earlier.

Except it's not exactly that.

As said on Mettaton's wiki page, he has a possible cousin whom could be Mad Dummy. Napstablook is a cousin of Mettaton's. Because of the lietmotif of Ghost Fight used in Dummy!, I think Napstablook and Mad Dummy are related to eachother. Now, that brings Muffet into the question. Although there is no sign of any connection, they could be cousins like Napsta and Mad Dummy possibly could be.