Causes choking, possibly suffocation
- Ginny Weasley: "You can't come down here! No, sorry, you're going to have to go round by the swivelling staircase, someone's let off Garrotting Gas just along here -"
- Surly Hogwarts student: "I can't see no gas."
- Ginny Weasley: "That's because it's colourless! But if you want to walk through it, carry on, then we'll have your body as proof for the next idiot who doesn't believe us."
- — Ginny Weasley claiming to dissenting passer-bys about the gas.[src]
Fred and George Weasley were planning to release some in Hogwarts School of Witchcraft and Wizardry in 1996, during Dolores Umbridge's tyrannical tenure as Headmistress, but they left the school before they had a chance. Their sister, Ginny, merely had to mention it to prevent students from traversing down a school corridor, which allowed Harry Potter and Hermione Granger to break into Umbridge's office to use her fireplace for communication.
A garrotte is a wirey weapon that can be used to strangle a victim, and also may refer to the action of "ripping through" something.
- Harry Potter and the Order of the Phoenix (Mentioned only)
- Harry Potter and the Deathly Hallows: Part 1 (video game) (First appearance)