Answers to anticipated questions:
-About 3″.
-I haven’t identified the species. (Some kind of Sphinx Moth larva? Does anyone know?)
-The head is on the Left.
-I don’t know what the green thing is. It looks like an egg.
There is a ton of info on the Web about caterpillars (e.g., here and here). However, there are so many distinct varieties that identification is difficult if you don’t already know where to look.