Wikia

Freezing Charm
Incantation	Immobulus; (eem-OH-bue-luhss)
Type	Charm
Hand Movement
Light	Blue
Effect	Renders targets immobile and disables Muggles' burglar alarms

The Freezing Charm (Immobulus), according to Horace Slughorn, will disable a Muggle burglar alarm as it stops things from moving. The spell strikes resemblances to the Flame-Freezing Charm, which negates the effects of fire. Hermione Granger used the Freezing Charm on pixies after Gilderoy Lockhart set them loose and failed to stop them with Peskipiksi Pesternomi. In 1996, Horace Slughorn used the charm to freeze the burglar alarms of Muggle houses he stayed in. Later that year, Albus Dumbledore used this spell nonverbally on Harry Potter to stop the latter interfering with the former's death ^[1]. Kingsley Shacklebolt possibly used this spell nonverbally during the Battle of Hogwarts.

Behind the scenes

In the film adaptation of Harry Potter and the Chamber of Secrets, Hermione freezes all the Pixies using this spell.
Remus Lupin also used this spell to freeze the Hogwarts Whomping Willow in the film adaptation of Harry Potter and the Prisoner of Azkaban.
Harry Potter uses a non-verbal version in the film adaptation of Harry Potter and the Goblet of Fire to freeze the Grindylows.
In LEGO Harry Potter: Years 1-4, when cast, the victim will emerge into a blue bubble, motionless. This is how Pixies are defeated. Once in the bubble, they must be shot again, breaking the bubble and their little bodies.
Kingsley Shacklebolt possibly used this spell during the Battle of Hogwarts to stop a Death Eater breaking through a window on the Quad Battlements.

Immobulus, from the Latin “immobilis”, meaning immovable.

↑ [Harry Potter and the Half-Blood Prince, Chapter 27, pg.584 of the American Edition "Expelliarmus was not a Freezing Charm".

Freezing Charm

Incantation	Immobulus (eem-OH-bue-luhss)
Type	Charm
Hand Movement
Light	Blue
Effect	Renders targets immobile and disables Muggles' burglar alarms