Polymorph Blade Greatsword (Lost Laboratory of Kwalish)

very rare · Melee Weapon 2024 · Requires Attunement

When you attack a creature with this magic weapon and roll a 20 on the attack roll, the creature must make a DC 15 Wisdom saving throw in addition to suffering the attack's normal effects. On a failed save, the creature also suffers the effects of a polymorph spell. Roll a d20 and consult the following table to determine the form the target creature is transformed into.

d20 New Form
1 Tyrannosaurus Rex
2 Giant Ape
3 Elephant
4 Giant scorpion
5 Rhinoceros
6 Polar bear
7 Giant toad
8 Giant eagle
9 Black bear
10 Crocodile
11 Wolf
12 Riding Horse
13 Ox
14 Giant frog
15 Poisonous snake
16 Hawk
17 Octopus
18 Cat
19 Rat
20 Rabbit

A creature is immune to this effect if it is immune to damage of the weapon's type, is a shapechanger, or has legendary actions.

Curse

This weapon is cursed, and becoming attuned to it extends the curse to you. Until the curse is broken with a remove curse spell or similar magic, you are unwilling to part with the weapon. Whenever you attack a creature with this weapon and roll a 1 on the attack roll, you suffer the effect of a polymorph spell for 1 hour, rolling on the table to determine your new form.

Heavy

You have Disadvantage on attack rolls with a Heavy weapon if it's a Melee weapon and your Strength score isn't at least 13 or if it's a Ranged weapon and your Dexterity score isn't at least 13.

Two-Handed

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

Mastery: Graze

If your attack roll with this weapon misses a creature, you can deal damage to that creature equal to the ability modifier you used to make the attack roll. This damage is the same type dealt by the weapon, and the damage can be increased only by increasing the ability modifier.