And what's going on?

Syndactyly, also known as syndactyly, is a common congenital deformity of the hand or foot.

Syndactyly is characterized by the structural union of some or all of the tissues of two or more fingers or toes, which may be caused by abnormalities in embryonic development. Syndactyly may be only skin connected, or may involve deeper tissue connections such as bones, tendons, blood vessels, or nerves.

Syndactyly may affect the appearance and function of the hand or foot and often requires surgery to correct it.