The haft of the weapon is a large metal pole, resembling an anchor, the bottom of which has a ring which attaches to a heavy mithril chain. The chain coils loosely up the length of the haft, and connects to the head, which is in the likeness of of a thick tentacle with barbed suckers. The tentacle goes out, then curves back in on itself so the tip sticks out and away from the re-curving side. This allows the wielder to choose on each strike to use bludgeoning or piercing damage. The Kraken's Boon is an oversized and heavy weapon, requiring 18 strength to be able to attune the weapon, and to be able to wield it without disadvantage.

After attunement, the Kraken's Boon is considered a +1 magical weapon and can on a Bonus Action be used to make a grapple check on any creature within 10 feet of a size large or smaller. The DC for this grapple check is your strength+2+proficiency. On a successful grapple, the tentacle animates and grabs the target, dealing 1d10 force damage per round until the creature escapes or is freed from the grapple. The hammer can not be used as a weapon while grappling*. While attuned to the Kraken's Boon, all strength checks made within a body of water are made at advantage, and you have water breathing. The Kraken's Boon hits all vehicles with advantage and deals an additional 2d12 damage to ships and water vehicles. At a character strength of 20 or higher, the Kraken's Boon becomes more powerful for its attuned wielder and unlocks new abilities as well as being considered a +2 magical weapon. It now gives its wielder free movement while within the Astral Sea or any body of water. The strength cap is removed up to 30 strength as long as you are attuned to the Kraken's Boon. If your strength is lower than 24, you may choose to use 24 as your strength for any strength check, including grapple checks. The Bonus Action grapple DC is now your strength+4+proficiency and can be used to grapple up to a giant sized creature with advantage. If a large or smaller sized creature is grappled by the Kraken's Boon, the hammer can still be used as a weapon, dealing an additional +1 damage for every size above tiny the grappled creature is, at the expense of -10 movement unless in water, or the Astral Sea. Damage dealt to opponents using this, is also dealt the the grappled creature as force damage as well as taking the grappling damage. Once per long rest, you can call upon Kraken's Boon to give a +2 bonus to armor class for up to one hour, which is boosted to +4 if you are in a body of water. The damage boost to ships and water vehicles is now raised to 4d12.