Box Of Friends

Box of Friends is an unlockable activated item added in Afterbirth.

Effect

 * Upon use, it adds one copy of each of Isaac's familiars for the duration of the current room.
 * If Isaac has no familiars, a Demon Baby will spawn for the duration of the current room.

Interactions

 * 1up! / Dead Cat: Familiars are multiplied but do not give Isaac additional lives.
 * Best Bud: If used before taking damage, the white fly will circle around Isaac. However, multiple white flies cannot be spawned, so using Box of Friends after taking damage or using it multiple times in a room has no effect.
 * Bob's Brain: Adds an additional brain. When used upon entering a room, Box of Friends eliminates the item delay, which allows Isaac to launch Bob's Brain immediately.
 * Car Battery: Adds two copies of each familiar.
 * Smart Fly: Very useful on Greed mode as each usage will add an attacking fly, killing enemies and bosses very quick.
 * Cube of Meat / Ball of Bandages: Upgrades the cube/ball for the current room. This can be used to easily unlock the Super Meat Boy and Bandage Girl achievements.
 * Daddy Longlegs: Familiar will be copied.
 * Pickup generating familiars: The copied familiars will drop pickups independently.
 * Guillotine: Duplicates the Head circling around Isaac's body. Only one head will shoot tears.
 * Incubus: Multiple Incubi which share the same tear modifiers as the player.
 * Isaac's Heart / Isaac's Head / ???'s Soul / Milk!: These familiars are not copied.
 * In the case of Milk, the familiar itself doesn't appear but instead it decreases tear delay by 2 (effective tears up) when used, without needing to take damage.
 * Key Piece 1 / Key Piece 2: Key pieces are multiplied, but do not complete the other half.

Trivia

 * The Box of Friends seems to resemble the Lament Configuration of the Lemarchand's box from Clive Barker's Hellraiser.
 * Might be a very obscure reference to a Yu-Gi-Oh! card with the same name.
 * This item used to have a recharge time of 2, until an update on November 4th, 2015.
 * When playing in Korean, this item still has a recharge time of 2.

Box Of Friends