Staff of the Adder

You can use a bonus action to speak the 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 ft. Your proficiency
bonus applies to the attack roll. On a hit, the target takes 1d6 piercing Dmg and must succeed on a
DC15 CON or take 3d6 poison Dmg.