Guppy's Hairball is an unlockable familiar in The Binding of Isaac.

Spawns a hairball familiar that loosely follows behind Isaac.

The familiar can block shots and be swung to damage enemies, dealing 5 damage per tick (21.43 per second).

Each time it kills an enemy, it grows in size and its damage increases by +2. It can grow up to 5 times, for a maximum of 13 damage per tick (55.71 per second).

The damage dealt by it is equal to: (level × 2) + 3.

Upon entering a new floor, the hairball decreases its level:
• If level 2, reverts to level 1.
• If level 3 or 4, reverts to level 2.
• If level 5, reverts to level 3.

This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this item for the previous Repentance version, check this page instead.

Become Guppy for the first time.

This item contributes towards the Guppy transformation. Collecting 3 items from this set will grant Isaac flight and spawn a Blue Fly 66% of the time when a tear hits an enemy.

Guppy's Hairball can be found in the following item pools:

The following tags are applied to this item:

The following special synergies and interactions for Guppy's Hairball have been documented.

* Note that not all possible synergies and interactions are listed here.

Below is the Internal Item Description as shown in-game.
Note that some stat changes are not displayed here. Please see the main description for the full effects.

Guppy's Hairball

• Familiar that follows Isaac and can be swung around to deal contact damage
• Blocks enemy shots
• Gains size and damage each time it kills an enemy
• Abyss: x1 locust .75x Isaac's damage

• Check out the item description on the external Isaac Wiki.