author of teenage fantasy book requires a new cover for novel - "Trevor the Burping, Farting Goblin"

This is what a business in United Kingdom was looking for in their book cover design

I would like a book cover for my humorous novel "Trevor the Burping, Farting Goblin" which is aimed at children ages 12-15

The blurb for the book is:
"Trevor is a goblin - a goblin with serious problems.
He farts, he burps, he is in a heap of trouble and he has just landed in the back garden of two teenagers.
Sisters Hannah and Phoebe are plunged into a world of mythical mayhem, troublesome trolls, uncivilized unicorns, dangerous dragons, a wicked witch and a lot of farting after Hannah finds the mean, green, stink machine in the bottom of her school bag.
Arrogant Trevor needs Hannah and Phoebe to help him save his world from a tyrant and together the three of them embark on an adventure filled with laughter, fantasy and danger as they attempt to bring peace to his land.
Trevor is a story filled with action, magic and a fair dose of sarcasm."

Trevor is described in the book as follows:

"The man is just under three feet tall with scrawny legs and arms covered in heavy, coarse black … Read more