— Great! Another present!
A few days ago, Oscar celebrated his birthday with his parents.
Today he got a parcel from his godfather who lived a long way away. Very excited, he rushed to open it and found... a money box in the shape of a pig. A pig that was green all over from its snout to its corkscrew tail. There was a little envelope with it. His godfather had written him a note:

Dear Oscar,
Here is a piggy bank for your birthday.
There is a secret inside that I hope you will discover!
Big hugs and kisses from your loving godfather.

Oscar was a bit disappointed. He'd have preferred a remote control car or a robot-dog. And anyway, what was he on about with this story of a secret? He didn't get the point of his godfather's letter!

Before he went to sleep he turned the piggybank in all directions trying to find out what secret was hidden inside. But no luck! He couldn't figure it out. He slid a few coins into it and fell asleep. But in the morning when he woke up he found the coins lying by the side of the piggybank, as though they had climbed out by themselves. He was sure he'd posted the coins through the slot before going to sleep...

Intrigued, Oscar put the coins back in the pig before going down for breakfast. But when he came back to his room, there were the coins again, outsides the piggybank.
— What's going on? he wondered.
Increasingly fascinated he slid the coins back inside the pig and then waited beside it, quietly, determined to solve the mystery of this green piggybank.

Suddenly, the pig began to shake. The coins came out of the slot all by themselves. Oscar couldn't believe what had happened. He was even more mystified when he suddenly heard a little voice say:
— Come on, that's quite enough!
— Er... is that you talking, little piggy? asked Oscar, feeling a bit nervous.
— Duh! As if pigs could talk! What a foolish idea.
And right then, right next to the piggy bank appeared a funny little person in a cloud of green, completely green, as green as the piggy bank.

Oscar's mouth hung open in shock. He had never seen someone as small as this. He must be dreaming, he thought.
— My name is Filch, said the tiny little man. And that, that is my house, he declared, pointing to the piggybank. If you drop coins inside it you're going to break all my furniture. So watch out!
Then he added in a jokey way:
— Your godfather told me that you were as smart as a monkey. But with your mouth hanging open like that you look more like a foolish fish!
Annoyed, Oscar closed his mouth... but then opened it straight away to ask all the questions buzzing round in his head.
— But who are you? What are you doing inside a piggybank? How do you know my godfather? Are you for real? Is this all a dream? What do you eat to make you so green? Spinach? Caterpillars? Or...
— STOP right now, shouted the leprechaun who had enough of all this cross-examining. How do you expect me to answer if you don't let me talk?
Seeing that Oscar was ready to listen, he began:
— I'm a leprechaun. I've lived in this piggybank for a long time, way before you were born. Your godfather found this pig when he was a young boy and just like you, he tried to put his coins inside. He had exactly the same expression as you, said the leprechaun, with a smile, when he found out about my existence! I'm green because I drank a badly made potion that made me like this. And finally, I do not eat caterpillars.
— But why did my godfather send you here? asked Oscar confused. Why to me?
— Your godfather thinks that you might be able to help get me back to my original colour. I need someone I trust to help me make the antidote. Your godfather is too old now... Even if he used the Shrinking potion he'd be too big to come with me. That's why he thought of you to...
— ‘Shrinking'? interrupted Oscar. There's a potion that can shrink you?
His new friend nodded.
— You're telling me you can make me as small as you? And there's also a potion that will make me big again?
— Of course there is! So do you want to help?
— Too right I do! Bet your life on it! High five, OK!
And Oscar reached out the palm of his hand which looked colossal compared with Filch's. The little man high-fived with his titchy hand and then said:
— Would you like to visit me in my house?
— Right now, you mean?
Oscar thought for a moment and then added:
— Today is Sunday and I've got nothing till lunch-time. Let's do it! Do I take a potion?
— No need, replied Filch. Give me your thumb. You'll see...
Slightly nervous, Oscar gave his thumb to the little green man, who took out a flask from his pocket and put a teeny drop of blue liquid onto Oscar's nail.
All of a sudden, there was an almighty WHOOSH! In a rush of blue cloud, Oscar had shrunk and found himself now the same size as his friend.
Completely enthralled he went through a secret door that was opened by Filch and inside the pig.
— Wow! he said to himself.
And this was only the beginning of the surprises.
Inside his miniature house, Filch began opening large cupboards where all sorts of potions stood in rows. Shelves full of flasks of all colours. Oscar had never seen anything so beautiful.
— I am a potion maker, explained Filch. I've got a book of recipes that I've invented, he added proudly. That one there, he said, pointing to a vial filled with a bright yellow liquid, makes wings sprout on whatever you like. I called it ‘Canary' because of its colour. It's useful for travelling but the effect doesn't last long. I always have to have several bottles ready with me just in case I drop down in the middle of nowhere! That one over there, he said indicating another vial, is a really useful potion if you've got nothing to eat at home. One drop on a plate and a wonderful meal appears before you...
Oscar stopped listening. Awestruck, he stared around at all the little bottles gleaming in all sorts of different colours. He felt like he was in the middle of a rainbow. Then all of a sudden the piggybank began to shudder. The bottles knocked against each together, making a clanking din - cling, gling, glang!

What on earth was going on?
It was Slippers, Oscar's cat.
He had come into the room and heard the voices coming out of the piggybank. Being an inquisitive cat, he had nudged the green piggy to find out what was inside.
— Slippers, it's me. Stop! called Oscar.
But nothing was going to stop. The pet didn't recognise the sound of his master's voice and went on swatting the piggy that in turn began to shake and sway and then started to topple over in perilous fashion.
— Quick! Take cover! yelled Filch to Oscar as he saw the bottles begin to plummet from the shelves.
They both ran to a little wardrobe, slid inside and shut the door. High time; a minute later they found themselves tossed upside down.

Inside Filch's house they heard the sound of BANG! then PAFF, DZIIINNG, POUFF, BAMM and even K'POUM. All the potions crashed onto the floor, with the bottles smashing into a thousand pieces in a cloud of every colour under the sun.

Slippers was an inquisitive cat but also a bit of a coward. Terrified by all the strange noises, he raced as fast as he could out of his young master's room.

A few moments later, after making sure that nothing more was going to move, Filch and Oscar emerged from the wardrobe. Ouch! Their heads felt sore having been sent all topsy- turvy.

Their eyes took in the sight of a real battlefield! The potions were splashed everywhere and every single thing in the house was covered in colour. The leprechaun's bed had spider's feet that had grown instead of its feet and it was busy climbing up the wall making a web from the sheets.
The horse head shelves were neighing while bat socks were running around between the legs of the two friends.

A cup of tea was flying serenely past inside the piggybank, accompanied by a little teaspoon and a sugar bowl. All three were a shade of a bright yellow!
— But where's my teapot? asked Filch, watching them move. It's always put away next to the sugar bowl.
— There it is! called Oscar, flabbergasted, who had caught sight of the canary yellow teapot sitting on a fluffy chair...
— All the bottles are broken, he cried, slowing pulling himself together. I'm so sorry. Slippers is not a bad cat; he's just a bit stupid. How are we going to clear up?
— No problem, smiled Filch. Don't worry about tidying up! I've always got a special ‘Fix it' potion in my pocket in case something like this happens!
And in fact he brought out an unbroken bottle from his overalls. He opened it, poured a drop on to the floor and in a moment, everything was back to how it had been. That is, except for the cup, the spoon, the sugar bowl and the teapot which had flown up to the ceiling and didn't seem like wanting to come back down.
— I'll sort that out later on, said Filch. But it's annoying, he added, that even though all the bottles are back in their right place, they're all empty. I'll have to make all the potions again. Thank goodness, my recipe book was in a safe place.
He took a little wooden box from the wardrobe where he and Oscar had taken shelter. Inside it, the big book of recipes seemed in perfect shape.
— Now we just have to find all the ingredients. It'll take time but if you'd like to help me and be my assistant, we'll be fine.
Before Oscar could reply, they heard the sound of a voice shouting up to them:
— Oscar! Time to eat! Don't forget to wash your hands.
It was already lunchtime. Oscar got quickly out of the piggybank and promised his friend he'd come back as soon as he could.
— Wait, Oscar! called Filch. Aren't you forgetting something?
Oscar was still tiny. In his hurry he'd forgotten he'd changed his size. His new friend took out a green bottle from the special box.
— I always keep spares of the really important potions, he told the astonished young boy. Always better that way. Accidents can happen quickly - just like you've seen!
Feeling confident this time round, Oscar held out his thumb and POUFF, in a cloud of green he was back in a flash to his normal size.

Before going downstairs to have lunch, he turned back and waved to the little green man. His godfather had really given him an extraordinary present... and now he had a sense that he was going to have the most amazing adventures!