There are several animals that can get pregnant without mating. This process is called parthenogenesis, which means "virgin birth". While it's rare in vertebrates, it has been observed in several species, including crocodiles, sharks, and some types of reptiles. For example, a crocodile at a zoo in Costa Rica was found to have produced a fetus that was 99.9% genetically identical to her.
Parthenogenesis is more common in insects like mayflies, and it's even been observed in some species of stingrays. This phenomenon occurs when a female animal's egg develops into a viable embryo without needing to be fertilized by a male. While the exact reasons for parthenogenesis are still being investigated, it's believed to be a survival mechanism for certain species, allowing them to reproduce even when males are scarce.
