This costume was for Western Day at my school. I knew right away that I wanted to be a cactus, but figuring out how to do it was more difficult. In the end I came up with a very easy way to make this costume.
Double Sided Sticky Tape
First, you will need a long piece of cardboard, as this will be the center trunk of the cactus. Crease this cardboard so that you can make it into a cylinder and tape the two ends of the cardboard together.
To make to arms of the cactus, use more cardboard. It doesn’t matter if the cardboard has to be squished and misshaped to make the right frame. Once you cover it with paper, you won’t be able to tell a thing. To attach the arms, you will need to cut holes in the main body of the costume and secure the arms on the inside with lots of tape.
Once you have the frame, cover with green paper using double sided sticky tape. Then, cover the green paper with bubble wrap. The green will show through as bubble wrap is pretty transparent.
Finally, stick toothpicks as spines all over, but make sure they are not too sharp as so nobody gets hurt.