Far away in the tropical waters of the Coral Sea, two prawns were swimming/walking/crawling around - one was called Justin and the other was called Christian.
The prawns were constantly being harassed and threatened by sharks that inhabited the area and one day Justin said to Christian, "I'm fed up with being a prawn; I wish I was a shark, and then I wouldn't have any worries about being eaten"
A large mysterious cod appeared and said, "Your wish is granted"
Lo and behold, Justin turned into a shark.
Horrified, Christian immediately shot away, afraid of being eaten by his old mate
Time passed (as it does) and Justin found life as a shark boring and lonely. All his old mates simply ran away whenever he came close to them. Justin didn't realise that his new menacing appearance was the cause of his sad plight
While swimming alone one day he saw the mysterious cod again and he thought perhaps the mysterious fish could change him back into a prawn. He approached the cod and begged to be changed back, and, lo and behold, he found himself turned back into a prawn.
With tears of joy in his tiny little eyes Justin swam back to his friends and bought them all a cocktail (the punch line does not involve a prawn cocktail - it's much worse).
Looking around the gathering at the reef he realized he couldn't see his old pal.
"Where's Christian?" he asked.
"He's at home, still distraught that his best friend changed sides to the enemy and became a shark", came the reply
Eager to put things right again and end the mutual pain and torture, he set off to Christians' abode and, as he opened the coral gate, memories came flooding back.
He banged on the door and shouted, "It's me, Justin , your old friend, come out and see me again!"
Christian replied, "No way man, you'll eat me. You're now a shark, the enemy, and I'll not be tricked into being your dinner."
Justin cried back "No, I'm not. That was the old me. I've changed. I've found Cod. I'm a Prawn again Christian"