Decoy Detonator

• Type: Magical Device, Joke Product
• Owners: Fred Weasley and George Weasley (creators), Harry Potter
• Maker: Fred Weasley and George Weasley of Weasleys' Wizard Wheezes

A Decoy Detonator is a small, discreet magical object designed to create a diversion. In its inert state, it is described as looking like a “black horn-type object.” It is small enough to be surreptitiously dropped from a person's hand or bag without being noticed. Once activated, the device moves of its own accord, adding to its effectiveness as a distraction.

The primary function of a Decoy Detonator is to create a significant and sudden diversion, allowing the user to move or act without being observed. The device is activated simply by being dropped. Upon activation, it scuttles away from the user, often heading towards a populated area or a place where its detonation will cause maximum disruption. After a short period of movement, the Decoy Detonator explodes with a loud bang and releases a large quantity of thick, pungent, black smoke. The combination of autonomous movement, a startling noise, and a visual smokescreen is highly effective at drawing the attention of anyone in the vicinity.

The Decoy Detonator was invented by Fred Weasley and George Weasley as a product for their joke shop, Weasleys' Wizard Wheezes. It was part of their successful line of magical prank and utility items developed during their time at Hogwarts and perfected after they opened their shop at Number 93, Diagon Alley. By the summer of 1996, Decoy Detonators were available for purchase alongside other popular items like Peruvian Instant Darkness Powder and U-No-Poo.

• Harry Potter and the Half-Blood Prince: Harry Potter purchases Decoy Detonators during his first visit to Weasleys' Wizard Wheezes. Later in the school year, he attempts to use one to get past Argus Filch in a corridor. His goal was to listen in on Draco Malfoy, who he suspected was using the Room of Requirement. Harry dropped the detonator, which successfully distracted Filch, but Malfoy emerged from the Room of Requirement and caught Harry before he could properly investigate.
• Harry Potter and the Deathly Hallows: A Decoy Detonator proves crucial during the trio's Infiltration of the Ministry of Magic. While in the Atrium, disguised with Polyjuice Potion, Harry, Ron Weasley, and Hermione Granger are about to be separated by Ministry of Magic wizards. To create a diversion, Hermione drops several Decoy Detonators from her enchanted beaded bag. The devices scuttle away and detonate, filling the area with noise and thick black smoke. This causes enough chaos for the trio to slip away from the crowd and enter the lifts leading down to the department levels.

• In the Harry Potter and the Half-Blood Prince video game, the Decoy Detonator is a usable item that functions as it does in the novel, creating a loud noise and smoke to distract characters. (video game)