Goner

Goners are rare monochrome "copies" of other beings that form chiefly from manifestations attempted by a single being, or from a small number of spontaneous manifestations. They appear visually similar to the beings which they take after, but entirely grayscale and with various small differences. All goners are, by their nature, yarov, although some that resemble humans in appearance and behavior do exist, and their existence was taken advantage of by the Yahiraban for their state of being (these human-goners were also parents in all known boss yaref lineages, including the Mimiga type and Ketsukane family found in Yarzon-Ebott).

One notable goner is Goner Kid, who was created by and as a copy of Monster Kid and is their "best friend" sister. Another example is Gaster.