Draw a simple pencil drawing of a castle protected by three walls

Draw a simple pencil drawing of a castle protected by three walls, each one represents the skin, symbolizing hypodermis the dermis the epidermis. At the entrance to the castle, represent small vehicles that symbolize the epidermis, and joined spheres that symbolize the dermis, and robots that symbolize the hypodermis, and all of them carrying gifts towards the castle walls. Use arrows to show the movement of these vehicles, spheres and robots heading to the castle, delivering their gifts inside the castle.