The animal kingdom had become overpopulated.
The lion, being the head of the animal kingdom, made a decree: A joke telling contest would be held at the end of the week. The tortoise, unanimously agreed upon as being the fairest of all the animals, was appointed as the official judge. The rules were simple: tell your joke to the tortoise, and if he laughs, you can stay, but if he does not, you are banished. The competition would continue until the population of the kingdom was reduced in half.
All the animals spent the rest of the week preparing. Never before in the animal kingdom had so much original content been created. Jokes upon jokes were imagined, tweaked, and committed to memory. The animals worked tirelessly, until finally, the joke telling day came.
All the animals were gathered in a great assembly. Before animals were chosen at random to present their jokes, an offer was extended to any animal who thought they had a truly exception joke. The zebra volunteered almost immediately. It was not very often that he got to go first at anything because of that whole pesky "Z" thing. Additionally, he felt that his joke was quite funny, and wanted to make sure that he got a chance to present it to the tortoise before the tortoise was tired of laughing.
He nervously approached the podium, and presented his material. It was short, sweet, and had an excellent punchline. To the zebras relief, the whole animal kingdom erupted in a roar of laughter, and it fact, it took several minutes for everyone to calm down...
...except for the tortoise. Without emotion, he just stared back at the zebra. The zebra was shocked, the rest of the kingdom astonished, but sadly, everyone knew what this meant. The zebra was escorted away, never to be seen from again.
It came time for the second animal to give his joke. Again, they polled for volunteers, and after some hesitation, the chimpanzee raised his hand. The chimp figured it had a good repertoire of making others laugh, and while the tortoise was apparently a tough crowd, he figured he probably had a decent shot. He had worked hard on this, and had about a five minute act.
The chimp's animatedly presented his finest material. It was a bit song, a bit dance, and a ton of humor. The kingdom chuckled throughout the act, but when the chimp dropped his final punchline, the kingdom went berserk. Never before had such a funny joke been told: the whole act, while funny in itself, was the perfect setup to the final line. This was not a joke, it was a work of art.
Once everyone had again calmed down, all eyes were on the tortoise. He was unmoved. The chimp was astonished, the kingdom flabbergasted. The chimp was escorted away.
At this, no one dared to volunteer. Two masters of the craft were just set away. How could anyone compete? There was silence across the animal kingdom. Everyone felt the weight of the impending doom that was their fate. There were no more volunteers, their only hope was to not be called. All they could do was wait.
It was then than the bison was called. He lumbered up to the front. He took a big gulp; he knew he really wasn't good at joke telling anyway, and was pretty sure that he was destined to fail He hesitated, stuttered, stammered, but presented his joke to the best of his ability anyway. When the punchline was delivered, (or at least what seemed to have been whatever punchline there could have been at such a scenario,) there was a collective moan over the kingdom.
The joke, was it even a joke? was horrible. Everyone knew that he would be escorted away to his...wait, what? The tortoise! He began to chuckle. Not just a "heh" chuckle, this was a real chuckle. Not a chuckle, this was a lough! Then more and more! He was laughing so hard he was having a hard time catching his breath. How could this be? Did the tortoise have some strange sense of humor? Why was he laughing at this? Was he senile? The kingdom was sent into confusion.
Finally the lion interjected. "SILENCE!" he shouted. He addressed the judge: "Oh wise and fair tortoise, why is it that you find the bison's joke so humorous, but none of the other animals' jokes?"
"What Bison?" replied the tortoise. "I was laughing at the zebra's joke!"