a steam engine train riding tracks in the mountains, the thin black smoke writes the words "CHOO CHOO" in the sky. the smoke from the engine looks like a black snake of black vapor writing "choo choo" in a cursive font. the airy texture of the letters is that of a fluffy cloud of coal smoke, blending with the smoke trail from the engine, like a photoshop montage, the letters and the smoke are one and undistinguishable, letters made of smoke as if written with magic by an air bender, the black engine is attached to a long train of green wagons,