It's like some cats that are half-half with their coat colour! Although it's mostly just the face.It’s real! Very rare, it happens when two fertile yolks create one egg. The budgie that comes out has two different sets of dna.
Perhaps you’ve seen a “mash-up” video, where two or more recordings/elements are blended to create a new version. Nature has its own type of “mash-up” that can happen during the early embryonic stages of chick development. The result of this rare but natural phenomenon is referred to as a...lafeber.com