Liger
The liger is a cross between a male lion and a female tiger. It looks like a giant lion, with diffused tiger stripes. Like tigers (and unlike lions), ligers like swimming.Ligers exist due to human influence. In natural conditions tigers and lions do not inhabit the same territory so do not have the opportunity to form such a species cross.
Ligers grow much larger than tigers or lions. This is because female lions and male tigers transmit a growth-inhibiting gene to their descendants. Being the offspring of a male lion and female tiger, the liger does not have the growth-inhibiting gene and grows much more (as explained on a BBC program).
A cross between a male tiger and female lion is called a tigon.