BFFS!

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.
    • 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 Dark Bum which is unaffected.
  • Some familiars have unique synergies.

Notes

• The size change is only cosmetic: familiars' hitbox for blocking damage or attacking is not affected.
• Familiars summoned by a trinket or by Monster Manual are also affected by BFFS!.
• The Blue Flies and Blue Spiders benefit from Hive Mind instead.
• Does not increase the frequency or effectiveness of Status Effects applied by familiars.

Synergies

• BBF/ Bob's Brain: Doubles impact damage and increases explosive damage by 25.
• (Added in Repentance) Bird Cage: Spawns 4 rock waves in an x pattern. Doubles the damage when the bird lands and doubles contact damage. Damage of waves unaffected.
• (Added in Repentance) Blood Oath: Adds 2 extra full hearts worth of bonuses if any health is drained.
• (Added in Repentance) Holy Water: Double water damage, spawn a blue flame at point of impact.
• (Added in Afterbirth) Incubus: Shoots tears that do (Removed in Repentance) 2x Isaac's damage (Added in Repentance) 1.5x Isaac's damage. Still deals 2x as (Lilith) Lilith.
• (Added in Repentance) Isaac's Heart: Fires additional shots in random directions and leaves a larger puddle of creep. Does not change the heart's size.
• Juicy Sack: Spawns an extra Blue Spider.
• (Added in Afterbirth †) Lil Spewer: Increases the creep pool's size, but not its damage.
• (Added in Repentance) Lost Soul: Gives the Lost Soul a Holy Mantle effect.
• (Added in Afterbirth †) Mystery Egg: Spawns a champion variant of an enemy, even if the enemy normally can't be a champion.
• (Added in Repentance) Stitches: On use, fires eight tears from Isaac's original location. The tears synergize with Isaac's tear effects.

Interactions

• (Added in Repentance) Blood Puppy: Only increases the damage and size while it isn't hostile.
• (Added in Afterbirth) Evil Eye: The eyes are not treated as familiars and therefore will not synergize with BFFS!
• Guillotine/ Scissors: Doesn't change the head's size, but still improves its damage.
• (Added in Repentance) Hive Mind: Does not stack.
• (Added in Afterbirth †) Shade: Retains the increased damage even after being absorbed.