How about a green caterpillar cake or centipede in motion?

Make a bundt cake...or two. (Invision this first using bagels or doughnuts.) Cut in half and join the halves to make an S shape. Ice with tinted green icing and decorate with licorice for legs, suckers for antennae, gumdrops for eyes and M & M's for spots. Split red licorise makes a great tongue. You could place it on a bed of ground chocolate wafers to simulate dirt.

This was always the cake that my kids loved for their birthday parties and it's also easy to cut and serve.