A bezoar is a stone taken from the stomach of a goat and it will save you from most poisons.
7 seconds sound clip from the Harry Potter and the Sorcerer's Stone movie soundboard.
You can hear this line at 00:55:49 in the Blu-ray version of the movie.
Quote context
[...]
- Pity. Clearly, fame isn't everything... is it, Mr. Potter?
- Clearly, Hermione knows. Seems a pity not to ask her.
- Silence.
- Put your hand down, you silly girl!
- A bezoar is a stone taken from the stomach of a goat and it will save you from most poisons.
- As for monkshood and wolfsbane, they are the same plant, which also goes by the name of aconite.
- Well... why aren't you all copying this down?
- Eye of rabbit, harp string hum. Turn this water into rum.
- Eye of rabbit, harp string hum.
[...]