A dizygotic twin may or may not be a dragon and phoenix fetus. Twin-egg twins are formed when two fertilized eggs are fertilized at the same time and implanted separately in the meconium layer of the uterine wall, and each develops and grows into twins. The two separate fertilized eggs inherit different genes from their parents, so they may be of the same sex or different, and their appearance is usually different, and their personalities may be different when they grow up. The formation of dizygotic twins is mainly related to race, genetics, and the number of fetuses to some extent, and can also result in dizygotic twins if oral ovulation-promoting drugs are taken in the clinic. Twin eggs and twin fetuses are not necessarily the same as dragon and phoenix fetuses.