Urban Legends Reference Pages: Photo Gallery (Liger): I found this on Snopes this morning. I bet this Liger has gone off some sweet jumps. According to the Wikipedia article, here’s why Ligers are so big:
Ligers grow much larger than tigers or lions and it is believed this is because female lions transmit a growth-inhibiting gene to their descendants to balance the growth-promoting gene transmitted by male lions (this gene is due to competitive mating strategies in lions).
Being the offspring of a male lion and female tiger, the liger inherits the growth-promoting gene, but does not have the growth-inhibiting gene and typically grows larger than either animal; this is called Growth dysplasia.