Teratomas are tumors composed of multiple tissue types that arise from embryonic germ cells. They are typically found in the ovaries, testes, sacrococcygeal region, and brain. Mature teratomas contain fully differentiated tissues and are generally benign, while immature teratomas may be cancerous. Sacrococcygeal teratoma is the most common fetal teratoma, occurring in around 1 in 35,000-40,000 births. Prenatal diagnosis allows for treatment planning and improves survival rates. Surgery is the primary treatment for teratomas.