Sacrococcygeal teratoma is the most common congenital neoplasm in neonates. We came across a post term (42 weeks) newborn baby girl delivered by normal vaginal route. The baby presented with a large soft, cystic mass over the sacrococcygeal region. Radiological examination showed a soft tissue mass with variegated appearance. Complete excision of the mass was done. Histopathological examination revealed the mass to be a mature sacrococcygeal teratoma with the extremely uncommon finding of a complete adrenal gland within the teratoma sac. Sacrococcygeal teratoma is a component of a continuum with other tumors including fetiform teratoma, fetus in fetu, parasitic and conjoint twins.