BFFS!

BFFS! is a passive item.

Effects

 * Visually increases the size of all familiars by 25%, and improves the effectiveness of most of them.
 * Doubles the damage of Familiars that deal damage through tears and contact damage.
 * Only affects familiars that deal a set amount of damage. Has no effect on most familiars that scale with Isaac's damage.
 * Has no effect on Creep generated by familiars.
 * For pickup-generating familiars, increases the frequency that they drop pickups.
 * Familiars that require clearing a certain number of rooms will require one less room.
 * Familiars that have a random chance to drop items have a higher chance.
 * Familiars that pick up consumables require less, except which is unaffected.
 * Some familiars have unique synergies.

Synergies

 * : Spawns 4 rock waves in an x pattern. Doubles the damage when the bird lands and doubles contact damage. Damage of waves unaffected.
 * /: Doubles impact damage and increases explosive damage by 25.
 * : Adds 2 full hearts worth of bonuses if any health is drained at all.
 * : Double water damage, spawn a blue flame at point of impact.
 * : Fires additional shots in random directions and leaves a larger puddle of creep.
 * : Spawns an extra Blue Spider.
 * : Increases the creep pool's size, but not its damage.
 * : Spawns a champion variant of an enemy, even if the enemy normally can't be a champion.
 * : Gives the Lost Soul a effect.
 * : On use, fires eight tears from Isaac's original location. The tears synergize with Isaac's tear effects.
 * : Shoots tears that do double Isaac's damage.

Interactions

 * Only increases the damage and size while it isn't hostile.
 * The eyes are not treated as familiars and therefore will not synergize with BFFS!
 * /: Doesn't change the head's size, but still improves its damage.
 * Does not stack.
 * Retains the increased damage even after being absorbed.

No Effect
The following familiars will appear larger, but gain no actual benefits.

Trivia

 * BFF stands for Best Friends Forever.
 * This item is used in The Family Man (challenge #19) and Scat Man (challenge #36).