Staff of the Adder

Requires attunement by a cleric, druid, or warlock.
You can use a bonus action to speak this staff’s command word make the head become an animated snake for 1 minute.
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 Con save or take 3d6 poison damage.
The staff has 15 AC and 20 HP while animate and is destroyed if reduced to 0 HP.