This tattoo leaves the marking of some deep sea creature, three of it's limbs extend and wrap around the users flesh. While the tattoo is on your skin, you can, as an action, cause the tattoo to extrude into inky tendrils, which reach for a creature you can see within 15 feet of you. The creature must succeed on a DC 14 Strength saving throw or take 2d6 bludgeoning damage and be grappled by you. As an action, the creature can escape the grapple by succeeding on a DC 14 Strength (Athletics) or Dexterity (Acrobatics) check. The grapple also ends if you halt it (no action required), if the creature is ever more than 15 feet away from you, or if you use this tattoo on a different creature.

As a Bonus Action the Player may also make a contested athletics roll with the target creature(s) and may pull the target creatures 10 feet towards themselves.

This item only has three charges and recharges after a long rest (each charge is represented by a the inky tendrils on the tattoo, after each use the corresponding tendril slightly fades). 

A player can choose to use multiple charges of their tattoos, either ensnaring multiple creatures or using all three on one creature. If multiple tendrils are used on one foe they have to make multiple strength saving throws but can only take a maximum of 4d6 damage. 

Tattoo Attunement. To attune to this item, you hold the needle to your skin where you want the tattoo to appear, pressing the needle there throughout the attunement process. When the attunement is complete, the needle turns into the ink that becomes the tattoo, which appears on the skin. If you have multiple magic tattoos, they count as a single magic item with regard to the number of magic items you can attune to. If your attunement to the tattoo ends, the tattoo vanishes, and the needle reappears in the closest unoccupied space to you.

"That is not Dead which can Eternal Lie. And with Strange Aeons even Death may Die."

-A Message from the Deep