If you wanna learn to draw Jimmy, do it the same way you studied George. Copy the first few poses exactly, proportions, construction etc. to get used to him. The drawings near the bottom are harder because the poses are more complicated, so don't start there. This is my favorite face of Jimmy above. I've never been able to recapture his joyful look of discovery with a hint of evil.
Here's Jimmy after a diet of potato chips and sodas. Now he starts getting complicated. Don't be distracted by all the wobbly details. They all flow along his central line of action and basic silhouette.