Water bomb snail

I found this charming little snail while browsing Pinterest. Its shell is a water bomb, which you inflate just like the traditional model. As the diagram was in Chinese (well, I think so), I have no idea who designed this model. The original model is folded from an 8.7 x 21 cm rectangle (that is, the rectangle left over when you cut a square from an A4 sheet), which gives it a long tail (the yellow one in the photo), but I find it also works well with a square cut in half (10.5 x 21 cm): that gives a bigger shell (the red and blue ones in the photo), which also makes it easier to inflate.