For the outdoor animations, I ran iStopMotion on our Macbook laptop.  The hatching egg was one of those toys you put in water.  The figure inside swells and expands, ‘hatching’ from the non-soluble eggshell.  The hatching and growing actually took three days - I compressed it into 20 seconds.  When you buy the egg, you don’t know what animal will hatch.  The boys were very worried that it would be a stupid duck instead of a cool snake or alligator. So, the hatching was filmed through water and a mom donated a blue bucket that I could easily key out. 

The egg drop and bounce were stop-motion; the egg hung from fishing line.

Mutant Egg