Dinosaur cake for granddaughter 12 22

My granddaughter at the age of two seems to like dinosaurs. I was therefore commissioned by her mother to decorate one of my wife's chocolate sponge ring cakes with a dinosaur theme. I thought that it would be good to add a little something to the design and put a surprise in the well in the centre covered by the mini marshmallows, which were masquerading as the bubbling larva in a very active volcano.