Guppy's Hair Ball

Guppy's Hair Ball is an unlockable passive item.

Effects

 * 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.
 * 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.

Trivia

 * This item is used in Cat Got Your Tongue (challenge #8).
 * The function and flavor text of this item might reference the idioms "no room to swing a cat" and "can't swing a dead cat without hitting...".
 * In the original The Binding of Isaac, Guppy's Hairball did not count towards the Guppy transformation.