A guy is driving down the street and sees a sign in a yard - Talking Dog for Sale, $10.
Intrigued, he parks, walks up to the house, and knocks on the door. An older man answers, and our guys says, "I'm here about the talking dog." The old man says, "He's around back, follow me."
They go around back and find a pretty nondescript mutt, maybe a labrador/spaniel mix, getting on in years. The owner prompts, "Ask him anything you want."
Feeling a little foolish, our guys says, "So, you can really talk, huh? Tell me about yourself."
The dog perks up and replies, "Glad to! I had a more or less normal puppyhood, until one day I asked my owner to take me out for a walk. She nearly fainted and then called the FBI - the X-Files were big back then. The government took a real interest and decided I might be useful to the CIA. So, they sent me to Monterey to learn a couple languages and then started airdropping me into hostile nations to gather intelligence.
"I have to admit, it was pretty exciting stuff, and I found myself in a bit of hot water more than once. After a while, though, it got to be too much - it's a young dog's game and there was a pretty close call in North Korea that I'd rather not talk about. So, they brought me back to the States and I was assigned to the DEA to do undercover narcotics work in South and Central America. Again, fun work, though I picked up a habit that took a few years to break.
"Once more, I sort of outlived the job, and they brought me up to McLean. The plan was to see if they could replicate my special talents in a breeding program. Brother, I was up to my eyeballs in bitches. No complaints about that job, nosiree. Unfortunately, it looks like I'm a one-off - lots of beautiful pups but nothing more than a bark coming out of any of them. After five years, the government gave up and just tossed me in with an auction of surplus office equipment. That's how I ended up here."
"Wow," says our guy, "that's amazing!" Turning to the old man, he adds, "I gotta ask - why only ten dollars?"
The old guy, disgusted, replies, "Because he's a f***ing liar! He never did any of that s**t!"