How to Make A Little Green Monster ‘I Can Save The Earth’ Costume

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‘I Can Save The Earth’ book is a firm favourite in our house. Max, the little green monster, is a bit of a nightmare. He creates mess, he leaves taps running, he litters, he doesn’t care about anyone else, and he certainly doesn’t give the environment a second thought… Until one day, the power goes out. He steps outside and sees the beautiful full moon, the spring flowers and listens to the wildlife – he realises the world has wonders he has never taken in before. In the summer, he visits the beach and notices the sand and shells, he watches dolphins and collects litter to go in the bin. In autumn, he plays in the leaves and composts them, and in the winter, he realises how magical even one tiny snowflake is. His newfound love of the earth sparks a change in him. He no longer wastes water or electricity or creates mess. He now recycles, passes items on and even hugs trees. Max learns that the Earth is precious and needs protecting. The ideal book for any young budding environmentalist and a unique character to go as for World Book Day or other dress-up days your child may have. We made this costume for World Book Day 2025 and this is how we did it…

What You Will Need:

• Green trousers

• Green (fluffy) jumper

• Toy stuffing

• Sewing kit

• Blue cape or material to make a cape from

• Green card

• Cardboard

• Elastic

• Scissors

• Pen and colouring pens/pencils/pastels

How To Make The Little Green Monster Costume

The Body

As Max’s body is very round in the book, I wanted to clearly show this in the costume, but without making it uncomfortable for my child or impossible for him to sit at school. After a bit of consideration, I decided that my best option was to create a round body from a jumper. I found a fluffy green jumper on Vinted that looked like it had some stretch in it. I purchased some toy stuffing from Hobbycraft (you can easily get this online too) and found some old pyjama bottoms in the house that I could cut up to create the pouch to hold the stuffing inside the jumper.

Now, I am not at all good at sewing and I do make my crafts up as I go along so this make was all about guesstimates and hope!!

I began by cutting the leg area of the pyjamas (adult size) to give me one long piece of material. I then began to sew the bottom of this to the bottom of the inside of the jumper, leaving it loose enough to move with the jumper and my child.

I then carefully stuffed the pouch I created with the toy stuffing which may sound simple but this actually took up a lot of time because I had to keep checking I had the right amount to get the desired look.

I also found that overstuffing led to pulling on the threads I had sewn and that the shape of all the material changed when I asked my child to try it on. So, be prepared to be patient. Once I was happy with the look, I hand-stitched around the top of the material to finish the belly.

The Cape

We didn’t own a blue cape, and unfortunately, I couldn’t find one secondhand anywhere (I always try my best to choose secondhand and using what we already have over buying new). I did, however, find a bright blue top in a charity shop which I cut perfectly into a cape shape and it luckily had a button fastening which came in handy to tie it on the front.

The Mask

My child doesn’t particularly like face paints, so we chose to make him a mask for his costume. I drew a rough outline of the shape of the Little Monster’s face, including his horns, mouth and eyes and cut it out. Once I was happy with the shape I used pastels to shade, colour and finish off the look. To secure the mask, I cut a piece of elastic to the right size and simply attached it to the back using brown tape.

The Sign

The Little Green Monster holds a sign in the book that says Keep The World Beautiful! So we decided to make this too. This is just a piece of cardboard with the words written on with a cardboard handle.

The Finished Look

I finished the look by popping a green t-shirt under his jumper, he wore trainers for comfort and of course, held his book.

This was such a fun make and it could really work for any green monster, green alien or even The Grinch at Christmas or Halloween (he is creepy afterall!)

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