This one... I got distracted by the details of the penguin (the Tail ... that's evil, but also the small lines of the hand ).

Here comes the rhinosss. I like how the light and shadow line weight exercise adds volume to the rhino. And after watching the demo, I can see how the hierarchy of importance of line weight that I did here is lacking some contrast and organic feel to the strokes ( i.e. there can be more variety within one line, especially if it's the line with much emphasis like the nose).