Lord Akeldama's dirigible, also called "Buffety." In Heartless, Lord Akeldama sends his drones to rescue Alexia in this craft. The vampire cannot use the airship himself, but all fashionable gentlemen keep dirigibles, so he does the same.
In Curtsies & Conspiracies Felix Mersey asks Sophronia, "Is that all I am to you? A plaything, a speck of dust on a sunbeam, a bit of dandelion fluff on the breeze?" (Chapter 6). There may, in consequence, be a connection between Felix and/or Sophronia and Lord Akeldama's dirigible's name. Or Gail is simply playing.