It has since been removed.

A baby boy in Brazil was born with a real human tail that was successfully removed in surgery. The case was reported in the the Journal of Pediatric Surgery Case Reports, which described the boy's mother as healthy who didn't drink alcohol or do drugs but smoked 10 cigarettes per day throughout pregnancy. The baby boy was delivered prematurely at 35 weeks through an uncomplicated vaginal delivery. Initial assessment revealed the infant was jaundiced and had a 12cm-long human tail with a ball at the end of it, Fox News reports. Around 40 cases of real human tails have ever been recorded in the medical literature, according to the Journal. The report says that at around the fourth week of gestation, most of us start to grow a tail in the womb. This usually disappears by week eight, morphing into the tailbone (or coccyx). An ultrasound was carried out to rule out any neurological involvement in the child's tail so that doctors could assess whether it could be safely removed. Once the ultrasound showed no neurological involvement, the baby was taken to the operating room and the tail was surgically removed. The article classifies human tails as either true or pseudo-tails. Sometimes when parents think their child is born with a real tail, it’s really a pseudo-tail, which can be a symptom of a tailbone abnormality or spina bifida, according to the report.