whangdoodle
A whimsical monster in folklore and children's fiction; a bugbear.
"A whangdoodle! What's that?"
"I'm n-n-not a tor-tor-tortoise," stuttered the curious creature, "I'm a wha-wha-whang-whang-doodle."A term of disparagement.
obsolete
For a man who can listen for an hour to Mr. White, the whining, nasal, Whangdoodle preacher, and then sit down and write, without shedding melancholy from his pen as water slides from a duck's back, is more than mortal.
A ruling in which the opening stake limits are doubled for the next play after the appearance of a very good hand.
It is sometimes agreed in advance that after a hand of certain rank, such as Four of a Kind or a Full House, is shown, a Whangdoodle or Jackpot must be played[…]
Where it comes from
Of American origin. First use appears c.1856. Popularized by appearing in a sermon parody attributed to William P. Brannan as "Where the lion roareth and the whangdoodle mourneth for her first-born," published in The Harp of a Thousand Strings: Or, Laughter for a Lifetime (1858). Roald Dahl uses the term in at least three stories of his: James and the Giant Peach, Charlie and the Chocolate Factory, and The Minpins. In at least two of those stories, namely Charlie and the Chocolate Factory and The Minpins, the whangdoodle is stated to be a vicious monster.
Adapted from the Wiktionary entry whangdoodle (CC BY-SA 4.0).