What does "crafty" mean? Is this word common?
"Crafty" here means "creative". A "craft" in this context is a creative project, which here is making different mechanisms for delivering Halloween candy to trick or treaters safely. Therefore, "crafty" here means "creative" in the context of making a "craft", which is a creative project. "Crafty" in this context is a known word, but it is not very common in conversational English. This word is mostly only used by people who regularly make "crafts". Ex: She is crafty, she loves to make jewelry. Ex: I am feeling crafty today, let's make something.