Maybe you have already heard this one, but here it is anyway:

A guy is driving around and he sees a sign in front of a house:

“Talking Dog For Sale.”

He rings the bell, and the owner tells him the dog is in the backyard. The
guy goes into the backyard and sees a Labrador Retriever sitting there.

“You talk?” he asks.

“Yep,” the lab replies.

“So, what’s your story?”

The Lab looks up and says, “Well, I discovered that I could talk when I was
pretty young, and I wanted to help the government; so I told the CIA about
my gift, and in no time at all they had me jetting from country to country,
sitting in rooms with spies and world leaders, because no one figured a dog
would be eavesdropping. I was one of their most valuable spies for eight
years running.” “But the jetting around really tired me out, and I knew I
wasn’t getting any younger so I wanted to settle down. I signed up for a
job at the airport to do some undercover security work, mostly wandering
near suspicious characters and listening in. I uncovered some incredible
dealings and was awarded a batch of medals. I got married, had a mess of
puppies, and now I’m just retired.”

The guy is amazed. He goes back in and asks the owner what he wants for the
dog.

“Ten dollars.”

The guy says, “This dog is amazing. Why on earth are you selling him so
cheap?”

“Because he’s a liar. He didn’t do any of that shit.”

Botta bing!