Supernumerary body part

Many additional body parts form by the same process as conjoined twins: the zygote begins to split but fails to completely separate.

[13] A chimera is an animal or plant that has two or more different populations of genetically distinct cells that originated in different zygotes that have merged.

Anatomical structures are typically mixed depending on which cells are prevalent in different body parts.

This was particularly notable in the cult of Artemis (Diana) celebrated in the ancient city of Ephesus, in modern Turkey.

In Hungarian mythology, having six fingers on a hand (polydactyly) is held to be the sign of innate supernatural power (see táltos).