This video shows you how to get the skull that is hidden in Bad Piggies Ground Hog Day Bonus Level 1-IV. If you zoom out a bit, you’ll see a skull above the starting point. Build a contraption using a tnt box and soda bottles. Launch your contraption high by detonating the tnt. Then quickly trigger the gas bottles so that the pig is sent to the left on the skull above. Timing is crucial!
If you have a different strategy for completing this level feel free to leave a comment below.