This video shows you how to get the skull that is hidden in Bad Piggies Ground Hog Day Level 1-23. If you zoom out, you’ll see a skull in the cave to the right. Navigate your pig in position, on the hill to the left. Detonate the tnt to send the pig flying very high above the mountain. The pig should land on the grass patch above, then roll down in the tunnels onto the skull below.
If you have a different strategy for completing this level feel free to leave a comment below.