Old Man and His Dog

There was a policeman who was on patrol, when he saw an old man walking down the street with a box on a leash.
"Poor old man" he thought, "I better humor him at least".
So the policeman walks up to the old man and says "That's a nice dog you've got there!"
"It's not a dog, it's a box," the old man replied.
"Oh, I apologize," the policeman said. "I thought you might have been confused" He returns to his patrol.

The old man turns to the box and mutters, "We fooled him that time, eh, rover?"