Beetle eyes are a common potion ingredient.
Over the course of his education at Hogwarts School of Witchcraft and Wizardry, Harry's trunk had accumulated a layer of filth along the bottom including, among other things, desiccated beetle eyes. Harry cleaned out this mess while packing for his final departure from 4 Privet Drive in 1997.
- Harry Potter and the Philosopher's Stone
- Harry Potter and the Philosopher's Stone (video game) (GBC version)
- Harry Potter and the Deathly Hallows
- Harry Potter Trading Card Game