This one is from Mark Brooker and the "six smelly bikers"

There were these two prawns, Troy and Christian, sitting in their hole in the bottom of the ocean and Troy says, "I'm bored being a prawn and I've heard that Neptune, that God of the sea bloke, has powers that can transform you into more interesting things".

So, Troy sets out across the seabed in search of Neptune and after a couple of days comes to Neptune's palace. He explains his problem to Neptune who asks Troy what he would like to become: Troy says he would like to be a crab with a big claw and Zap! Neptune tranforms him into a crab.

Troy rushes back home to show Christian his big claw but after a couple of days, he reralises that crabs walk sideways and he had been going in the wrong direction. Anyway after about a week of sideways walking Troy gets home and bangs on the door saying "Christian, I'm home".

Christian however refuses to open the door saying "You're not my friend Troy, you're a horrible crab with a huge claw thats going to eat me".

Troy is very upset and decides to go back to see Neptune and get transformed back into a prawn. About a week later he get back to Neptune who, after some debate, agrees to turn Troy back into a prawn.

As a prawn, troy only needs two days of walking to get back home and he bangs on the door saying "it's me, Troy, I'm home". But Christian refuses to open the door saying "you're not my friend Troy, you're a big crab that's going to eat me up".

Troy replies:

"I'm a prawn again, Christian"