Sometimes babies are born with teeth. It's weird and maybe even disturbing to you, but that's just the way it is.
It's OK, they aren't born with a full set of teeth or anything. Most children start getting their first baby teeth at around six months, but one in every 2,500 babies is born with one or two little, wiggly teeth. They're sometimes yellow and always fragile because, while the mineral enamel of normal baby teeth has had the chance to calcify, the enamel of natal teeth is predictably under-done and fragile.
Unless their roots are rock solid, these early bird chompers are usually just pulled out by a dentist. Not only are natal teeth a tough break for nursing mothers for obvious reasons, but because they generally have few or no roots, they can fall out on their own. That's the last thing you want to happen because your baby can choke on her own preemie little tooth. Of course, once the tooth is removed, there will be a gap there amongst the rest of the baby teeth until an adult tooth erupts to take its place. It's really no big deal, dentally speaking.
Long ago, natal teeth were thought to be an omen of things to come for the baby who bore them. In Malaysia, they were thought to be a sign of good fortune, but in many places in China children born with teeth were considered monstrous. According to the Roman natural philosopher Pliny the Elder, natal teeth were very good luck for boys and very unfortunate for girls.
But according to a 2014 literature review published in the Indian Journal of Dentistry, genetics probably plays more of a role than cosmic omens: 15 percent of babies born with natal teeth have close relatives who were born with a weird little tooth, as well.