Trampling Crossbow

This heavy crossbow carries with it the force of a raging bull. When you roll a 20 on an attack roll made with this magic weapon, the bolt transforms into a spectral stampede immediately after it hits the target. When it does, the target and up to 2 other targets of your choice that you can see within 15 feet of it must make a DC 13 Strength saving throw. On a failed save, a target takes 1d8 bludgeoning damage, and if it is Large or smaller, it's pushed 10 feet away from you. On a successful save, a target takes half as much bludgeoning damage and isn't pushed. This bludgeoning damage is doubled against objects and structures.

Ammunition: You can use a weapon that has the ammunition property to make a ranged attack only if you have ammunition to fire from the weapon. Each time you attack with the weapon, you expend one piece of ammunition. The ammunition of a firearm is destroyed upon use. Drawing the ammunition from a quiver, case, or other container is part of the attack (you need a free hand to load a one-handed weapon). At the end of the battle, you can recover half your expended ammunition by taking a minute to search the battlefield. If you use a weapon that has the ammunition property to make a melee attack, you treat the weapon as an improvised weapon (see "Improvised Weapons").

Range: A weapon that can be used to make a ranged attack has a range shown in parentheses after the ammunition or thrown property. The range lists two numbers. The first is the weapon's normal range in feet, and the second indicates the weapon's maximum range. When attacking a target beyond normal range, you have disadvantage on the attack roll. You can't attack a target beyond the weapon's long range.

Loading: Because of the time required to load this weapon, you can fire only one piece of ammunition from it when you use an action, bonus action, or reaction to fire it, regardless of the number of attacks you can normally make.

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

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.

Proficiency: martial, heavy crossbow Source: The Griffon's Saddlebag: Book Two p. 177 (Third Party)