Ten bucks says you won't do it.

So this man walks into a bar, and notices a large jar on the counter stuffed with cash. He orders a drink, and he asks the bartender, "What's the deal with the jar?"
The bartender replies, "You put ten bucks in, complete the challenge, and you win the jar."
"So what's the challenge?"
"Sorry mate, that's not how it works, you have to pay to find out."
Curious, he agrees and gives the bartender ten dollars.
The bartender pull a large bottle of pepper tequila out and places it on the counter.
"Ok, so you have to chug this entire bottle of liquor and not vomit. After that, the biggest, meanest pit bull you ever seen in your life is out back. He's got a sore tooth and you have to pull it out. Lastly, there's a ninety year old woman upstairs who has never had an orgasm. You have to make things right before she dies."
Frustrated, the man yells, "Fuck that! No one's stupid enough to do any of that!"
"Well, that's why the jar has so much money in it."

After a few hours of drinking, the man comes back to the bar really drunk and says, "Fuck it, is my money still good for that challenge?"
The bartender informs him that it is and brings out the bottle of tequila.
The man chugs the entire bottle of tequila, and slams the bottle down with a wince on his face.
He stands up and walks out the back door. Immediately, the bar hears the dog's barking and the man yelling in pain. About thirty minutes later, it quiets down.
Everyone in the bar is wondering if they should get up and check to see if the man is ok. Right before the bartender could finish telling someone to go check, the man comes bursting in the door, barely standing, clothes ripped, and bloody as hell.
Everyone asks him if he's ok, and walks straight up to the bartender and drunkenly says, "Now where's the woman with the sore tooth?"