Source: Critical Role

Staff, ???

The Blightstaff is a knotted wet-looking wooden magical staff that is covered in lichen and topped with a large uncut amethyst. When activated, the dozen small knot holes within it begin to exude dozens and dozens of small flying beetles that swarm out of the staff onto the ground.

As a bonus action, the Blightstaff allows the wielder to summon a swarm of flying beetles once per long rest that act on the wielder's turn and can make a bite attack within a range of 30 feet. The swarm lasts for one minute and does 4d4 piercing damage.