Ligers, tigons and grolar bears, oh my! Take a look at some of these otherworldly hybrid animals and you'll realize the possibilities are endless. Though they rarely occur in nature, individuals from different but closely related species do occasionally mate, and the result is a biological hybrid — an offspring that shares traits from both parent species. You may have heard of the mysterious sheep-pig creature, but it turns out that one isn't a true hybrid. Here are six bizarre, but truly unique half-breeds...