The Hydra is a Flail of unknown origin that was left for the Cleric of Tiamat Donner.
It has a black reptile skin handle with a silvered, spiked pommel. The cross guard, also silvered, is of 2 dragon claws facing away from each other; open, as if trying to grab something.
There are attachments for 5 different flail head attachments. Attachments add to the overall damage and bonus damage of Hydra, depending on the enchantments on them.
This attachment has a Silvered Mace-Head (1d8), with an Adamantine Chain (+2).
When using this weapon, roll to-hit with the Base entry, then roll damage on each different Hydra entry.
Proficiency with a Flail allows you to add your proficiency bonus to the attack roll for any attack you make with it.
This weapon has the following mastery property. To use this property, you must have a feature that lets you use it.
Sap. If you hit a creature with this weapon, that creature has Disadvantage on its next attack roll before the start of your next turn.
Notes: Damage: Bludgeoning, Sap