Source: turtle confusion(book), by Barry Newell
The above are the collection of challenges suggested by Barry Newell in the book - Turtle Confusion.
Feel free to choose any of those 40 challenges and tinker around with the code to produce something similar. Also, it will be great if you can share that in the thread below along with specifying the pattern number.
During the exploration, if you discover something new, share that as a challenge for the community members too! We would also love to hear the stories/insights of your discoveries. You can also re-publish the same as a new topic in the turtleChat.