A dog was crossing a river bridge with some meat in his mouth.
Suddenly, he saw his own shadow(影子) in the water, and thought it was another dog with a bigger piece of meat.
He dropped his piece of meat and attacked the other dog, to try and get the bigger piece from him.
So he lost his piece of meat, which dropped into the river and floated away(漂走).
MORAL: It is not wise to be too greedy(贪婪的).