Egg

The Egg is the unhatched love child of Ash and Lillie.

History
During an unspecified time period, Ash and Lillie had unprotected sex and caused the conception of a Pokemon egg.

Sometime after the events of "A Ship at Sea", Lillie laid an egg at British NASA Space Camp. Due to the nature of the pregnancy, Lillie had no memory of the delivery.

In "A Warm Couple", Ash and Lillie decided to raise the egg, despite Lillie not being keen on being an un-wed pre-teen mother. However, Lillie protected the egg from being eaten by Ash's "Girlfriend" before getting booted out of the window by him. Lillie has now adopted a dedicated maternal ethic towards raising the egg.