Death comes to all, but the nightmare is eternal,
Within the Night Serpent’s maw and gullet, we become one,
To work in life towards the day when she will be freed,
And take solace in the oblivion that awaits, of that to take heed,
Such was the favored one’s fervor, to work in her cause,
To strike down even his father, who had fallen short of keeping faith with her laws,
A stave of many serpents in one he did craft and forge,
To commune with her in all her glory, his own nightmares for her to feed and gorge,
Guided his people did he under his rule, wielding conviction in her and his own power,
Her symbol made manifest, amid that even his enemies could only but cower,
At last, his enemies routed, his life’s work complete, and his mate laid down to be entombed,
So he laid beside, his breath departing as soul to enter oblivion, within the Serpent’s gullet to be consumed. - Religious Rite of the Staff of the Night Serpent, transcribed by Anastaysia Chuvoskary.
This black staff appears to resemble a snake, from its tail at the bottom of the staff, and all the way up to the serpentine head at the top, which has a pair of rubies encrusted onto the surface to resemble a set of red eyes. This staff was once used part of the regalia of the High Priest of the people of Ihl, as a symbol of the High Priest's station and devotion to Dendar, the Night Serpent.
While you are attuned to this staff, you feel confident and self-assured, and can speak, read, and write Abyssal and Draconic.
You can use a bonus action to speak this staff's command word and make the head of the staff become that of an animate poisonous snake for 1 minute. By using another bonus action to speak the command word again, you return the staff to its normal inanimate form.
You can make a melee attack using the snake head, which has a reach of 5 feet. Your proficiency bonus applies to the attack roll. On a hit, the target takes 1d6 piercing damage and must succeed on a DC 15 Constitution saving throw or take 3d6 poison damage.
The snake head can be attacked while it is animate. It has an Armor Class of 15 and 20 hit points. If the head drops to 0 hit points, the staff is destroyed. As long as it's not destroyed, the staff regains all lost hit points when it reverts to its inanimate form.