Friends and enemies in the animal world tend to be pretty clear-cut -- there are some species that just weren't born to get along. But as these unlikely pairs show, even Mother Nature doesn't set things in stone: Who says that orangutans and tigers, dogs and deer, cats and birds can't all be friends somehow?
From a sheep that brought a baby elephant out of a deep depression to natural enemies that snuggle down together for every nap, these 10 heart-wrenching relationships are incredible and unforgettable.
The Pigeon and the MacaqueTake this macaque, for example, who, according to The Daily News, was rescued from Neilingding Island in China after his mother abandoned him and left him for dead: His recovery was dragging until he made friends with this pigeon, and now the two are rarely apart.
Photo via The Daily Mail