- Seamus Finnigan: "What's that he's drinking, do you suppose?"
- Harry Potter: "I don't know, but I don't think it's pumpkin juice."
- — Harry and Seamus when they see Crouch drinking from the hip flask[src]
This flask was stolen by Bartemius Crouch Jr in 1994 when he was disguised as Moody and was teaching the Defence Against the Dark Arts class. He used it to hide some Polyjuice Potion, and would drink from it periodically to maintain his disguise. As Moody was well known to drink only from the flask, Crouch was able to take the potion in front of others without arousing suspicions. Over the year, Crouch would refill the flask with the potion periodically, stealing ingredients from Severus Snape's storeroom. Ultimately, when Harry Potter returned from Voldemort's rebirth ceremony, Crouch forgot his hourly intake in his excitement (ran out in the film adaption), and Albus Dumbledore emptied the flask's content onto the floor to show Harry (in the film adaption, Snape sniffed the empty flask to figure out the contents).
After the reveal of Barty Crouch, Moody took his flask back and cleaned it from the potion. However, Moody filled it with Polyjuice Potion again in 1997 some minutes before the Flight over Little Whinging as six people had to disguise them as Harry Potter. After a brief argument with Harry, who was initially refusing to let six people to risk their lives, he reluctantly gave a few strands of his hair to add into the flask to complete the potion, and Moody split the contents into six egg-cup-sized glasses, each for one of the would-be impostors, while warning everyone that the Polyjuice Potion tasted like "goblin piss". Moody himself did not drink the potion.
When Moody was killed and his corpse recovered by the Death Eaters, it is unknown what happened to the flask.
Behind the scenes
- The Noble Collection sells an exact replica of the flask, for around $30.
- In the novel version of Harry Potter and the Deathly Hallows, Moody simply took out "a flask of what looked like mud", with no mention it was his personal hip-flask, but the part 1 film adaption, the potion came from this specific container, with the content not shown due to the non-transparency of the flask.
- The film version shows the flask to have the top in the design of a human head with wings, which was not stated in the original novels.