We won’t make you sell your soul to get this Black Butler travel tumbler. Perfect for any fan, this environmentally friendly carnival cup includes a reusable straw and a spill-proof lid. Show the love for Black Butler on the go this Summer! A carnival cup is a cup made out of plastic. It is most commonly used as a container to hold beverages. Some are reusable while others are intended for a single use followed by recycling or disposal. Carnival cups are often used for gatherings where it would be inconvenient to wash dishes afterward, due to factors such as location or number of guests. Plastic cups can be used for storing most liquids, but hot liquids may melt or warp the material.