In The Graveyard Book’s Interlude chapter, we encounter The Jacks of All Trades. This is a reference to a popular figure of speech: “Jack of all trades, master of none.” Generally, this figure of speech refers to an individual with a variety of satisfactory skills, but with no real expertise.

The Jacks of All Trades in The Graveyard Book is the fraternal organization and brotherhood to which the primary antagonist Jack Frost belongs. It is likely called The Jack of All Trades to reflect the variety of antagonistic trades, or specialties, of its members.

The other members of this secret society are named after famous English Jacks. Jack Tar was an English term for a sailor belonging to the Merchant or Royal Navy, and now serves as a common nickname for anyone who goes to sea. Jack Ketch, also known as John Ketch, was an executioner for King Charles II in the late 1600s. Jack Nimble is a reference to “Jack Be Nimble”, an English Nursery rhyme from the early 1800s:

Jack be nimble
Jack be quick
Jack jump over
The candlestick

Jack Dandy is a reference to the English term “jack-a-dandy,” which essentially refers to a vain, conceited kind of person.

It is likely that these characters adopted code names or nicknames upon joining The Jacks of All Trades, as is common practice in secret societies. These nicknames are meant to preserve anonymity but are also likely based on their specialties. For example, the original folklore character Jack Frost is simply a personification of winter, but Jack Frost in The Graveyard Book is a murderer, and his nickname possibly refers to his cold-bloodedness.