Once upon a time, a magician was performing on stage. He said he could make a rabbit disappear. He waved his wand, said the magic words, and opened the box. But instead of the rabbit disappearing, his assistant was gone. The magician was so shocked that he accidentally turned himself into a carrot.
A man went to the dentist. The dentist said, 'You need a filling.' The man replied, 'No, I don't like fillings. I only like ice cream.' The dentist was so amused that he almost dropped his drill. Then the man added, 'Can you put ice cream in my tooth instead?'.
They are concise. For example, like 'The fish went to school. It got an A in swim class.' It gets the humor across quickly without a lot of extra words.
Once there was a magician on a plane. He told the flight attendant he could turn into a dove and fly off the plane. The attendant said, 'Show me.' So he did his magic trick. And the attendant said, 'Well, now go into the baggage compartment.'
A man was staying in a supposedly haunted hotel room. He heard strange noises all night. In the morning, he found out it was just the old radiator making those spooky sounds. Turns out the 'ghost' was just a creaky old heating system.
A dog decided to go for a swim in a pond. But when it got in, it realized it couldn't swim as well as it thought. It started paddling furiously and barking at the same time. A nearby duck just looked at the dog and quacked as if to say 'What are you doing?' The dog finally made it to the shore, looking very embarrassed.
A man goes to the doctor. He says, 'Doctor, you've got to help me. I keep thinking I'm a deck of cards.' The doctor replies, 'Sit down and I'll deal with you later.'
Surprise is a key element. For example, if a story starts with a normal situation like a man walking his dog, and then suddenly the dog starts talking, that's a big surprise. It makes the story funny.