BFFS!

BFFS! is a passive item.

Effects

 * Increases the size and doubles damage of familiars.

Interactions

 * BBF - Increases both the size and damage the explosion inflicts. This also makes it easier for Isaac to get hit by the blast.
 * Isaac's Heart - Increases the size of the hitbox, making it easier to get hit.

Synergies

 * Dry Baby / Fart Baby - The baby's increased size will make it easier to trigger the Baby's effect.
 * Guppy's Hair Ball / Samson's Chains - The increased size makes it much easier to hit objects/enemies while swinging the familiars.
 * Incubus - Incubus deals double your damage instead of copying it. Effectively doubles Lilith's damage.

Trivia

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

BFFS!