Missing Ingredient for the Emergency Antidote

d12
1. Ectoplasmic residue from a friendly ghost
2. Essence of solar flare
3. Cornea of a gorgon
4. One dozen pixie brains, whole
5. Flop sweat from the brow of currently reigning monarch
6. Werewolf vomit
7. Infected tooth of a giant
8. Pineal gland of a soothsayer whose uncanny prescience disallows surprise attack of any kind
9. Vial of tears from an innocent prior to execution
10. Two Cockatrice egg whites, beaten to stiff peaks
11. Willingly donated venom from the scorpion queen's stinger
12. First bud of spring from the uppermost branch of the colossal oak which also happens to house two competing clans of sentient giant wasps

Requested by John Harris