The Zhentarim Tattoo, resembles a Winged Snake. Once attuned to the tattoo you can only un-attune under the approval or direction from Davil Starsong

With the Tattoo attuned you have advantage on Deception checks made to interact with civic officials of Waterdeep (including Lords, magistrates, and Watch and Guard officers).

Shadow step. You gain the ability to step from one shadow into another. When you are in dim light or darkness, as a bonus action you can teleport up to 60 feet to an unoccupied space you can see that is also in dim light or darkness. You then have advantage on the first melee attack you make before the end of the turn. Once you use this ability, you must finish a Short or long rest before you can use it again.

Notes: approval by the Davil Starsong