A liger is the offspring of a male lion and a female tiger. Lions and tigers are part of the genus, although they are different species. It is also possible for a male tiger and a female lion to breed, although those offspring are generally called tigons. Interestingly, ligers will typically grow larger than either the parents.
It is standard zoo practice to keep the two species apart from each other, although breeding does still occur accidentally in captivity. There are an estimated 30 ligers in zoos in the USA, and 20 ligers in zoos in China. There are probably fewer than 100 ligers worldwide.
There are old legends of ligers occurring in nature, but they generally only occur while in captivity.
In December 2013, the first known white ligers were born in the Myrtle Beach Safari in South Carolina to a white male lion and a white female tiger.