Wizarding idioms

Wizarding idioms are expressions that are unique to wizarding culture. However, many of them seem to have analogous Muggle idioms, from which they may have been derived.

List of idioms

 * "Cat among the pixies" - play on "cat among the pigeons," which is also the name of a Hercule Poirot novel by Agatha Cristie, meaning to do something to cause a lot of people bother or worry. Specifically, Arabella Figg's description of Mundungus Fletcher.
 * "Wasn't room to swing a Kneazle"- play on, "No room to swing a cat", meaning it is very cramped. Used by Rubeus Hagrid to describe the area where the giants lived.
 * "Fell off the back of a broom" - synonymous with "fell off the back of a truck," meaning stolen merchandise. Mundungus Fletcher leaves his shift of watching over Harry Potter to see to such items, in 1995.
 * "Galloping gargoyles" - used by Cornelius Fudge and Professor Tofty when they express outraged shock.
 * "Get off his high hippogriff" - synonymous with "get off his high horse," meaning to stop being conceited - used by Rita Skeeter to describe Elphias Doge.
 * "Hanged for a dragon as an egg" - synonymous with "hanged for a sheep as a lamb;" if one is to be punished for committing minor offence anyway, one may as well go ahead with something even worse if it gets the job done better.
 * "Hold your hippogriffs" - synonymous with "hold your horses;" a request to wait for an explanation.
 * "It's no good crying over spilt potion" - synonymous with "it's no good crying over spilt milk," meaning it is no use worrying about unfortunate events which have already happened and which cannot be changed.
 * "Merlin's beard" - expression of surprise, synonymous with the Muggle phrase God's blood! Also, Merlin's pants, as exclaimed by Hermione Granger upon the realisation that Phineas Nigellus Black could see their location at 12 Grimmauld Place from his portrait. And also Merlin's saggy left... (the rest was unknown) by Ron Weasley to, and interrupted by, his father. Also Merlin's most baggy Y Fronts exclaimed by Ron Weasley when Hermione was holding the portrait of Phineas Nigellus Black.
 * "The fire's lit, but the cauldron's empty"- play on the Muggle phrase "the lights are on, but nobody's home," meaning someone seems to function correctly, but is actually somewhat dim. Used by Ivor Dillonsby to describe Bathilda Bagshot.
 * "To have a hairy heart" - means to be cold and unfeeling. Derived from the Beedle the Bard story The Warlock's Hairy Heart, in which a wizard cuts out his heart and seals it away in a crystal box, causing it to grow hair.
 * "Time is Galleons" - synonymous with "time is money", a Muggle adage about the time value of money.
 * "I'm so hungry I could eat a hippogriff" - synonymous with "I'm so hungry I could eat a horse" and the like, meaning so hungry that one could eat something as large as a hippogriff.
 * "Yanking your wand" - synonymous with "yanking your chain", meaning to joke around.