I added a wait block and change colour for each repeat within the Curve to show the recursion. I changed the starting co-ordinates for X & Y. I shortened the length of each side to make smaller concentric Koch Curves. Turbo Mode speeds up the creation of the 5 curves.
To see how this project works go to https://en.scratch-wiki.info/wiki/Recursion_and_Fractals "Recursion is the process of repeating items in a self-similar way. It can be implemented in Scratch by making a Custom block that runs itself. "