The Raven Staff is a Hardmode, post-Planterasummon weapon. It spawns a raven minion that chases enemies and deals contact damage. Like other minions, the summoned raven is invincible and follows the player for an unlimited amount of time, unless the player dies, summons a replacement minion, or cancels the buff. It is dropped from Pumpking during the Pumpkin Moon event (drop chance scales depending on what wave you're on: starts at 1.79%, reaches 14.29%).
Its best modifier is Ruthless. The Mythical modifier provides the widest array of stat bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, minions cannot deal critical hits. The only lasting advantage a Mythical Raven Staff has over a Ruthless one is knockback.