- Hermione Granger offered Harry Potter to soak his hand in a bowl of Murtlap Essence after he was forced to use a Black Quill that cut into the back of his hand in detention with Dolores Umbridge.
- Harry later recommended the same treatment to Lee Jordan after he suffered a similar detention with Umbridge.
- Lee later suggested that Fred and George Weasley use Murtlap Essence on the boils they got testing their Fever Fudge product. As Murtlap Essence proved to be a successful remedy for the boils, they were able to finally complete their Skiving Snackboxes.
- Harry Potter and the Order of the Phoenix (First appearance)
- Harry Potter and the Order of the Phoenix (video game) (Mentioned only)
- Harry Potter and the Deathly Hallows: Part 1 (video game)