Scratch Animation Reverse Engineering

A teacher friend in Oklahoma sent me the following video clip, which I converted to an animated GIF via Adobe. Her question to me was, “How did the student code this in Scratch?” Apparently the student did NOT save the project, so the actual code is not available for inspection and analysis. This is a Scratch coding reverse-engineering challenge, using the “pen blocks” like we do in my “Polygon Play” project, which is part of my Scratch animation unit!

I spent more time than I care to admit (more than an hour) playing with this code and tweaking it, and I did NOT come up with a satisfactory solution yet. Here are my two best attempts.

In “Circle Ray Animation v1” I’m trying to use the pen blocks, and I created two subroutines for the pin and pinhead. I’m pretty sure this is more complicated than what the student did originally. The student’s final graphic has 19 pinhead circles, but instead of fanning / drawing outward, they are at oblique angles which creates a “spirograph” like circle with a hollow center.

In my second attempt, I tried a different approach using the stamp block. Instead of creating a polygon with the “pen down” block and a loop, I tried “stamping” a sprite which I drew in the shape of a pin. I know this is not the technique the original student used, because they hadn’t changed the original Scratch Cat costume, but this result is actually closer to the design they created.

I tried “vibe coding” this challenge, initially using ChatGPT, then Claude, and finally Gemini. The LLMs offered the best help when I challenged them to “Please brainstorm 5 other ways to create this with totally different code approaches.” This is an AI prompting suggestion I picked up from Amanda Caswell in her October 2025 post on Tom’s Guide, “7 prompts I use for every AI chatbot — and they work for just about everything.” This is a version of her sixth prompt suggestion, “The ‘Three Versions’ Prompt.”

What ideas do you have? I’m thinking this could be a fun challenge to pose to my own middle school computer programming students down the road!