Spawns a hairball familiar that loosely follows behind Isaac, blocks shots, and can be swung like a flail to damage enemies.
The ball deals 5 damage per tick, but grows for +2 damage when it kills an enemy — up to 5 times for a maximum of 13 damage. The damage it deals per tick (each half-second) is (level × 2) + 3.
The hairball level decreases upon entering a new floor: if level 2, it reverts to level 1. If level 3 or 4, it reverts to level 2. If level 5, it reverts to level 3.
This item belongs to the Guppy set. Collecting three items from this set will transform Isaac into Guppy.