If it were to believed that the egg came before the Exeggcute, we would need to understand the existence of a more primitive form of Exeggcute that could allow our modern day Exeggcute to exist.
We may call this theoretical Exeggcute "Eleggtrocute."
Now this may give the idea that this former Exeggcute could be Grass/Electric typing. While this is merely theoretical, it may perhaps explain why there are naturally no more Grass/Electric Pokemon existing today. Perhaps the ancestor of Exeggcute live in an environment in which Electric Types could not thrive, and thus became Psychic type.
One counter argument to this theory would be that Exeggcute has no electric moves. In this instance, there may be a missing link.
