As we can see on this website, the liger is a real animal.

Bred for it’s skills and magic.

Update:
http://www.sierrasafarizoo.com/animals/liger.htm
http://www.tigers-animal-actors.com/about/liger/liger.html#liger
http://www.mosnews.com/news/2004/12/06/liger.shtml
http://home.hkstar.com/%7Emomo/wrestler/jtliger.htm