Slime: A book by David Walliams

Slime, from Children's author David Walliams.
WELCOME TO THE ISLE OF MULCH…
This little island is home to a large number of horrible grown-ups. The school, the local park, the toy shop and even the island’s ice-cream van are all run by awful adults who like nothing more than making children miserable. And the island is owned by the most awful one of all – Aunt Greta Greed!
Something needs to be done about them.
But who could be brave enough?
Meet Ned – an extraordinary boy with a special power. SLIMEPOWER!