The Hydra Staff is a craftable pre-Hardmode summon weapon. It summons a stone hydra servant. It attacks by throwing hydra chows at enemies. It can be upgraded to Doomite Radio.
Its best modifier is Ruthless. The Mythical modifier provides the widest array of stats bonuses, but these primarily affect the initial summon rather than the resulting minion. Additionally, minions cannot deal critical hits. The only significant advantage a Mythical Hydra Staff has over a Ruthless one is knockback.