Staff of Necrosteocytes

The Staff of Necrosteocytes is a Pre-Hardmode summon weapon that drops from Dark Casters. When used, it summons a small skeleton minion which runs along the ground to target nearby enemies. While it is moving, lingering bone cells are occasionally dropped from the skeleton.

Trivia

 * "Necrosteocytes" is a portmanteau of 'Necro', meaning death-related, and 'Osteocytes', a type of bone cell.