The Skeletalon Staff is a Pre-Hardmodesummon weapon that is dropped by the Ancient Avian. It summons two Skeletal Harpies directly at the cursor that seeks out and attacks enemies. Skeletal Harpies disappear after a few seconds or hitting an enemy. Summoning the minions does not affect the minion bonuses, meaning you can summon as much as you can.
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 sentry. Additionally, Minions and Sentries cannot deal critical hits. The only significant advantage a Mythical Skeletalon Staff has over a Ruthless one is knockback.