Portable Battering Ram (5e Equipment)
From D&D Wiki
Wondrous item, uncommon
This tiny battering ram is a little under 1 inch wide, 6 inches long, and weighs 1 pound. It has 3 charges and it regains 1d2 charges daily at each dawn.
As an action you can speak the ram's command word, expending a charge and causing the ram to grow tremendously in size. It now is 1 ½ feet wide, 10 feet long, and weighs 200 pounds, and can be used to break down sturdy doors and gates. It requires four characters total (two characters on each side of the ram) and adequate room to swing the ram to function properly while doing so. One character takes the lead in making the Strength check, and gains a +12 bonus to the roll.
Two more characters can assist in using the battering ram, giving the lead character advantage on this check. In the same vein, the battering ram can be used with only two characters, as long as they each have a Strength score of 15 or higher. However, they get disadvantage on the Strength check.
The ram remains in its expanded size for 1 minute, upon which it shrinks back down to its original size.