Ok let me try to explain why what you want to do isn't easy..
You want the sprite to be at mouse.x, mouse.y all the time, except when the mouse is overlapping the egg.
So you are going to have to tell the sprite what to do when the mouse is overlapping the egg. This is the hard bit, because you want it to follow the mouse, but it can't because the mouse is overlapping the egg. So you have tto tell the sprite how to follow the mouse, without overlapping the egg.
if you want to click somewhere and have the sprite go there you can use the pathfinding behaviour and it will go around the egg no problem.
But you choose to have the sprite at the mouse, so it's pretty hard to tell the sprite what to do when that is impossible.
So If you can find a simple way to explain in normal language where you want the sprite to be when the mouse is overlapping the egg and how to react when the mouse is no longer overlapping the egg, maybe than there is an easier way to explain it to the computer too.