Once there were three goldfish in different tanks, one had a castle, another had a treasure chest though it could not open without a key, which was in the third tank.  

They wanted to be in one tank together so that they could share the treasure and castle, but in order to do that they needed help from the Cat. 

And so they asked the Cat for help and the Cat replied, ''Why should I help you?'' The goldfish answered, ''Because we will give you half the treasure.'' The Cat agreed to help them.

One fish will eat the key, and the Cat will knock over the tank. The goldfish will be transported into another tank the one with the castle. Once inside the castle, he will vomit out the key because it was small and most likely would've gotten lost. Then the Cat will knock down the tank with the treasure chest which will not get lost. That goldfish will be transported into the other tank, then they'll celebrate in wealth.

THE PLAN

The goldfish ate the key.

''Are you sure about this? I don't want you to get hurt,'' the Cat asked. ''Yes,'' all the goldfish always said.

And so the fish went down.

CRASH!

The first part of the plan had worked! Now the goldfish who had ate the key would have to vomit it up, then the Cat will knock over the third and final tank.

He spat the key out.

CRASH!

Though the owner had it. ''THAT'S THE LAST STRAW!!!'' she yelled and started running.

MEANWHILE.

''Now about the treasure. Can you give it to me?'' the Cat said. ''No! We want the treasure all to ourselves,'' the goldfish said. ''What about the deal?!'' Cat said. ''The deal is off,'' the fish said. ''But I already helped you!'' Cat said.

''COME HERE CAT!!!'' the owner screamed. ''Ahhhhhhh!'' the Cat yelled.