cat’s paw, (be made) a

A dupe, a sucker who does another person’s dirty work. The term comes from an ancient tale about a monkey who wanted to get some roasted chestnuts out of the fire and, not wanting to burn his own fingers, got his friend the cat to use his paws for this purpose. There are numerous versions of the story in various languages; often it is a dog that is made the dupe, but in English it is the cat’s paw that has stuck over the years. Also see PULL THE CHESTNUTS