- Snape: "Boomslang skin. Gillyweed. Both come from my private stores, and I know who stole them."
- Harry: "I don't know what you're talking about."
- Snape: "You were out of bed on the night my office was broken into! I know it Potter! Now, Mad-Eye Moody might have joined your fan club, but I will not tolerate your behavior! One more nighttime stroll into my office, Potter, and you will pay!"
- Harry: "Right. I'll bear that in mind if I ever get the urge to go in there."
- — Snape confronts Harry about the theft of potion ingredients.[src]
The Boomslang Skin is skin shed from a Boomslang snake. The skin is mostly green in males and brown in females. It is an unusual potion ingredient, but is used in potions such as the Polyjuice Potion. Boomslang skin is not sold at the Apothecary in Diagon Alley but it can be found in the Potion master's private storage.
In 1992, Hermione Granger stole this ingredient from Snape's private storage in order to brew Polyjuice Potion as part of her, Harry and Rons' plan to try to get Draco Malfoy to admit that he was the Heir of Slytherin. In 1995, and possibly before, Bartemius Crouch Jr. stole this ingredient as well for the Polyjuice Potion needed to maintain his disguise as Alastor Moody. Snape later accused Harry of stealing it, though Harry incorrectly believed that Snape was referring to the 1992 incident, which Snape had long suspected him of being responsible for.
- Harry Potter and the Philosopher's Stone (video game) (GBC version only)
- Harry Potter and the Chamber of Secrets
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- Harry Potter and the Goblet of Fire (Mentioned only)
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