Hopping Mad

This idiom creates the image of someone hopping (jumping) up and down, enraged and furious. 

This expression comes from the early 1800's and has been a regular feature of English since. It is not meant to be taken literally, but to be a vivid expression of intense emotion.

Example: "The boss was hopping mad when he found out that someone had been stealing from his department. He's very determined to fire the person responsible."