Gaining Brood Tokens
When Eihort is the Ancient One, each time an investigator defeats a Cultist, that investigator gains a brood token. Also, any investigator who seals a gate gains 1 brood token.
Dangers of Brood Tokens
Each time an investigator gains a brood token, roll a die. If the roll is lower than the number of brood tokens possessed by that investigator, he is devoured.
Any brood tokens on an investigator who is devoured are immediately added to Eihort's doom track as doom tokens.
Brood Tokens in the Final Battle
Start of Battle: When Eihort awakens, each investigator gains one brood token.
Attack: The first player gains one brood token.