The Amulet of Wolfsbane

The Amulet of Wolfsbane contains, you got it, Wolfsbane. A northern European aconite. Aconite is a poisonous plant of the buttercup family, which bears hooded pink or purple flowers.Aconitum, also known as aconite, monkshood, wolfsbane, leopardsbane, mousebane, womensbane, devil's helmet, queen of poisons, or blue rocket, is a genus of over 250 species of flowering plants belonging to the family Ranunculaceae. These herbaceous perennial plants are chiefly native to the mountainous parts of the Northern Hemisphere, growing in the moisture-retentive but well-draining soils of mountain meadows. Most species are extremely poisonous and must be dealt with very carefully.

The Amulet of Wolfsbane is in possession of Queen Atossa. It was heard of in episode 6, The Battle of the Phoenix, and episode 7, The Hollow of the Kings.