Tell me more about this mysterious egg, Meredith. Is the tree in your yard? How did you spot the egg? Was it on top of the leaf or on the bottom? Color of egg? Maybe the people on the Plant ID forum could tell us what the tree is if you take pictures. That would help narrow it down. The only trees Spicebush use are Redbay, Swampbay and Sassafras. Most people can identify Sassafras since it's so distinctive. I love mystery eggs! At least you can keep feeding it the leaves from the tree it was laid on we can probably figure out what it is!