Tongue-Tying Curse

"Mimblewimble, which prevents your opponent from accurately casting their next spell."

- Gilderoy Lockhart discussing the use of the curse in Duelling.

The Tongue-Tying Curse (Mimble Wimble ), also known as the Tongue-Tying Spell, binds the target's tongue to keep him or her from talking about a specific subject. This feature also allows one to prevent the victim from incanting, and hence&mdash;like the Silencing Charm&mdash;it is useful when duelling (though could be overcome with more advanced magic). It is covered in the book Curses and Counter-Curses.

History
In 1992, this spell was taught by Gilderoy Lockhart during the Duelling Club to help students to better themselves.

In 1997, Alastor Moody set up curses to protect the Order of the Phoenix headquarters at 12 Grimmauld Place. One of these curses was this spell. It was so placed to prevent Severus Snape from revealing the area's location to Lord Voldemort, as the properties of the Fidelius Charm protecting the house made Snape a Secret-Keeper when Albus Dumbledore died. The curse was intended to both "keep him out and bind his tongue if he tried to talk about the place." It is unknown what would occur if Snape tried to write the location on paper, which would also have passed on the secret of the house's location.

Harry Potter, Ron Weasley, and Hermione Granger were affected by this curse when they sought refuge at 12 Grimmauld Place after fleeing Death Eaters in 1997. A sensation of cold air whooshed over them, causing their tongues to curl backwards, making it impossible for them to speak. Though their tongues soon unravelled again, Ron made retching noises and Hermione stammered for a while afterwards.

Known practitioners

 * Alastor Moody
 * Andrew
 * Bridget
 * Draco Malfoy
 * Edward
 * Emily
 * Gilderoy Lockhart
 * Harry Potter
 * Heather
 * Peter
 * Rachel
 * Rebecca
 * Roy
 * Stewart
 * Vindictus Viridian

Behind the scenes

 * In Harry Potter and the Philosopher's Stone, when Rubeus Hagrid found out that Harry had been told nothing of the wizarding world, he angrily rounded on the Dursleys, at which point Harry heard his Uncle Vernon whisper "something that sounded like 'Mimblewimble'".
 * A similar spell is Langlock, a curse invented by the Half-Blood Prince that glues the offender's tongue to the roof of their mouth.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Chamber of Secrets (video game)
 * Harry Potter and the Deathly Hallows
 * Pottermore