Corrosive Flail

Location - Corrosive Flail

Can be purchased from Derryth Bonecloak in Mycnoid Colony - Underdark. This is the Act 1 location.

There are three main ways to get into Underdark:

1. Go through Zhentarim's Base near the Waukeen's Rest. There is a lift behind the illusionary wall at the far end of the tunnel, near the wolves.
2. Enter through the Defiled Temple in Shattered Sanctum, Goblin Camp.
3. Enter through Teahouse, where you fight Ethel. You have to wear her special mask to see the illusion of the wall.