Corpse Slayer Greatsword

You gain a +1 bonus to attack and damage rolls made with this magic weapon. When you hit an undead creature with an attack using this weapon, the attack deals an extra 1d8 damage of the weapon's type, and the creature has disadvantage on saving throws against effects that turn undead until the start of your next turn.

Heavy: Creatures that are Small or Tiny have disadvantage on attack rolls with heavy weapons. A heavy weapon's size and bulk make it too large for a Small or Tiny creature to use effectively.

Two-Handed: This weapon requires two hands when you attack with it.

Proficiency: martial, greatsword Source: Explorer's Guide to Wildemount p. 266 (Third Party), Player's Handbook (2014) p. 149