Adamantine Punch Knife

Xanathar's Guide to Everything p. 78,

Type
Melee Weapon
Magic
Yes
Rarity
uncommon
Weight
3
Damage
1d4
Damage Type
piercing

Description

Sap (Mastery): If you hit a creature with this weapon, that creature has Disadvantage on its next attack roll before the start of your next turn.

Whenever you hit an object with this weapon, the hit is a critical hit.

Proficiency: simple, punch knife Source: Xanathar's Guide to Everything p. 78, Ben Huffman - Pugilist (Third Party)