So this couple takes a trip to some beautiful European City. They had planning it for months, and were excited and happy and the whole schmear. So they get there and are doing all the tourist things that Americans do. They find themselves sitting at an outdoor restaraunt one day when this cute little exotic dog comes up to them and starts nuzzling against their legs, being affectionate and so forth. So they feed it a few scraps from the table and then get up to leave. The dog follows them back to the hotel, and the couple decides to sneak it inside with them because they can't get rid of it. After a couple of days of this, they find themselves really attached to the dog.

The couple ends up taking the dog across the ocean and back to their home in america. Of course they immediatly bring it to the vet to have it identified and given the appropriate shots and so forth. Well, the after examining it for a couple of minutes with a puzzled look on his face, the vet asks "Has your dog ever barked?". After some thought, the couple realizes that it has, in fact, never emitted any sound of any kind. "That's no surprise. This exotic dog of yours is actually a giant rat."