Onion Rock is a trinket in Fiend Folio, a mod for The Binding of Isaac.

Spawns a Brickmin familiar that can be launched at enemies.

The familiar follows Isaac and can be launched in a chosen direction by using a fire button when the familiar is nearby.

The familiar's color is randomly chosen and is purely cosmetic.

Up to 4 familiars are spawned per floor. The first one spawns upon entering the floor, and consequent ones after every 4 rooms cleared.

The familiar does not do contact damage.

Multiple familiars are launched 1 by 1 instead of all at once.

Entering a new floor removes additional Brickmins and grants a random new one.

---

3 different Brickmin variants exist, each having its unique effects and behavior:

Square: slowly walks behind Isaac. When launched, performs a short-ranged slam attack that deals 2 × DamageStat + 3 × CurrentFloor damage to nearby enemies and confuses them for 2.67 seconds. After the slam, it goes to sleep, requiring Isaac to walk up to it in order to wake up.

Sharpe: quickly runs behind Isaac. Can be launched in a straight line and travels a long distance until it hits something. Applies a bruising effect to the enemy it hits for 6.67 seconds, making the enemy take +1 damage from all sources. Deals 3 × DamageStat + 3 × CurrentFloor damage to the enemy it hits, increased by +1 due to the bruise effect being applied first.

Sproingo: slowly hops behind Isaac. Can be launched in a straight line and rolls around the room, bouncing off of walls and enemies 4 times before stopping. Attempts to roll toward random enemies. Deals DamageStat + CurrentFloor damage to enemies it hits. Can sometimes lock onto an enemy after rolling, occasionally attacking it on its own.

The following special synergies and interactions for Onion Rock have been documented.

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

• Check out the trinket description on the mod's external Wiki.
• Download Fiend Folio from the Steam Workshop.