Shape to Form and Fantastical Creatures

Along with teaching Math in our charter school, I teach an art project for three hours each week.  I wanted to teach my 7th and 8th graders how to start creating 3-dimensional illusions on their 2-dimensional paper... in other words, how to make form using light.  I showed the students this tutorial on converting shape to form.  They followed along, and withing a few minutes they had shaded six shapes into 3-D forms. Then I asked them to invent a creature using a combination of the shapes they had just made.  They needed to indicate a light source on their paper, and we discussed shading accordingly.  Last step - add a scene around their creature indicating size.  
My sample creature is to the left. 

Here are a couple of screen captures from the tutorial, and some of the students' shape creatures.
We had a blast, and the results were fascinating.  Even those very reluctant to risk making art had success.  I forgot to name my creature, any ideas?