The Mollusc Staff is a Pre-Hardmodesummon weapon that is rarely dropped by Mussels. It summons a friendly mussel sentry that remains in place and lingers for two minutes before disappearing, firing bouncing pearls in sets of three in an arc that lands them directly on a stationary target. The pearls penetrate enemies and can bounce off of surfaces, slowly losing momentum as they bounce and eventually breaking on impact.
Its best modifier is Mythical unlike most summons. Ruthless raises the damage by the same amount due to rounding.