Abstract: An adjustable vent topper for the chimney of a kamado-style cooking smoker or oven. The vent topper allows for more precise control of temperature and smoke within the oven, and also allows for a decorative and entertaining display of smoke from a decorative article. The vent topper comprises a generally frustoconical body having alignable openings along the side of the frustocone for controlling the flow of air and smoke from within the oven. The vent topper further includes an opening in a chimney on the top surface of the frustoconical body for receiving a decorative article. The decorative article may be a nonventing plug or may be a decorative smoke-emitting article such as a smokestack, whistle, vehicle exhaust, gun, cannon, or other smoke-emitting object.