There's a Crocodile In Our Pool

There is a crocodile in our swimming pool.
Mum says I must learn to swim.
I can't learn to swim with a crocodile in our swimming pool.
Dad says I should close my eyes and just jump in.
He can't see the crocodile.
But it's there because I can see it.
The crocodile moves around the bottom of the pool with a long tail.
It has big teeth and it makes a grumbling noise.