Flesh flies (sometimes simply Flies) are small, usually irritating black flies with yellow blood that, as the name suggests, frequently fly around. These flies are used to distract a spider and let it smash hedges in the Hedge Maze of the Triwizard Tournament. Giant Purple Toads eat dead blowflies. While watching Sybill Trelawney's Divination teaching in the 1995–1996 school year, Dolores Umbridge said that she was just like a fly on the wall. In the 1996–1997 school year before Quidditch practice, Cormac McLaggen and Ronald Weasley had a discussion about the Keeper position. Ron said that a Keeper needed to be fast, and Cormac showed his fast movements by catching a fly with three fingers and crunch it.
- "I know Katie, she wouldn't hurt a fly!"
- —Harry Potter about Katie Bell[src]
In same year after Katie Bell was cursed with an opal necklace, which was observed by Minerva McGonagall and Severus Snape, Harry Potter said that Katie wouldn't hurt a fly.The home of Bathilda Bagshot were filled with flies, as it were very old and filled with chaos. Bathilda, herself, were smelling and had flies buzzing around her.
- Harry Potter and the Prisoner of Azkaban (video game) (First mentioned)
- Harry Potter and the Order of the Phoenix (film) (Deleted scenes mention)
- Harry Potter and the Half-Blood Prince (film) (First appearance)
- Harry Potter and the Deathly Hallows: Part 2
- LEGO Harry Potter: Years 1-4
- LEGO Harry Potter: Years 5-7