One day a dog was carrying home a piece of juicy meat in its mouth.
“Hmm, delicious” it thought as it walked.
On its way it came across a bridge, and looking in the water it saw its shadow reflecting in the water.
‘That dog has a bigger piece of meat than I do!’ it thought. ‘Maybe I can scare him into giving it to me.’
So the dog opened its mouth to bark at the other dog, but as it did the meat fell out of its mouth, into the water, and was lost.

Moral: If you are greedy, you may lose everything