Alehammer

The head of this weapon looks like a small ale barrel, although it is made out of steel and merely painted (convincingly) to resemble wood. On one end of the barrel is a cork stopper that can be removed to allow you to pour liquid into the barrel. The barrel can contain up to one gallon of liquid that wouldn't damage normal steel (e.g. water, ale, or mud).

If the barrel is full of liquid, you have a -2 penalty to attack rolls made with this weapon but hits deal an additional 2d4 damage. If the barrel is half-full, you have a -1 penalty to attack rolls made with this weapon but hits deal an additional 1d4 damage. You can uncork the barrel as a bonus action and the liquid will drain out at a rate of half a gallon per round.

If your Strength score is less than 15, you have disadvantage on all attack rolls made with this weapon.

Proficiency with a Warhammer allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Weapon Property: Two-Handed, Ignore Weapon Property: Versatile, Damage, Combat, Versatile, Push