There have been several famous cases of children being born attached at the head or other part of the body. In some cases, these children continue to live life as conjoined twins or are separated if medical professionals believe separation is an option. Craniophagus parasiticus is not the same as conjoined twin syndrome.

In rare cases, infants are born with a second head growing out of the primary skull. The second head is not attached to a functioning body in most cases. About 10 cases of Craniophagus parasiticus have been officially documented, but written literature is available for up to 70 more. Three cases of Craniophagus parasiticus has resulted in life beyond birth.

Two recent cases in 2003 and 2005 resulted in death of the living twin after the parasitic twin was removed. The only known case of an infant living with a parasitic twin was documented in Bengal. The “Two-Headed Boy of Bengal” died at the age of four from a snake bite.