Flail Head Poison is needed to create the Flail of Ages +5, but this is the first head which needs to be added to Flail of Ages +3 in order to make Flail of Ages +4. This head adds poison damage to the flail. This item appears in Baldur's Gate II: Throne of Bhaal.
|“||This is one of three flail heads belonging to Lord Arnise. Not all three heads are required to assemble the flail.||”|