The green slimey monster

There is a monster that lives in the sea
A wibbily wobbily blob is he
It has green slimey skin you see
With a massive body as big as can be

If you dare go out for a sail
Look out for the monster with a humongous tail
No one can miss it, you will not fail
Haha its just a sea-weeded whale

So they clean the sea-weed off its back
His skin underneath has started to crack
But they water it down & make it slack
Mr Whale plunges in the sea with an enornous crack