Forgotten Lullaby is a trinket added in The Binding of Isaac: Repentance.
- Doubles the rate of fire of Isaac's familiars.
- Familiars with charged shots will have their charge time halved. The recovery time between shots is not affected.
- This will double Lilith's fire rate since her tears come from an Incubus familiar.
- Does not affect wisps.
- This trinket was originally called Song of the Siren in Antibirth.
- Forgotten Lullaby, the trinket's new name in Repentance, is also the title of the secret room theme in Mudeth's original soundtrack for the Antibirth mod.