Lion-tiger hybrid proving a hit as keepers fight to ensure survival

His name is fit for a king, and he's being treated like one: Tsar the liger cub, born from an extremely rare lion-tiger romance, is proving a hit for a traveling Russian zoo.

Stretched out in the zoo director's van, the stripy Tsar - whose name is a throwback to the Russian emperors of centuries past - impatiently awaits his milk bottle.