Bison Staff (5e Equipment)

Rod, lengendary (requires attunement (druids only))

The Bison Staff looks like a tall, polished wooden staff, with a floating orangish-brown orb, when used, you can summon a herd of bison to attack enemies, they must make 2 dexterity saving throws, if they fail the first one, they are knocked prone, if they fail the second one, they take all the damage. Damage is: lvl 1-3 = 3d6+3, lvl 4-7 = 6d6+6, 5-9 = 9d6+9, 10-15 = 12d6+12, 16-20 = 12d8+20, if they succeed, they take half the damage, if not attuned, the person holding the staff and anyone nearby takes the damage too.