Booster Packs

Booster Packs were recurring content updates for The Binding of Isaac: Afterbirth †. Booster Packs contained popular community-developed mods as updates in the game continued to add features.

Booster Pack #
The first Booster Pack was released on March 23, 2017 on PC, and contains 9 new items, 3 new trinkets, and 3 new special cards, along with some new features.

Other Features

 * Dice Rooms now have a small icon in the corner of the room that denotes what the effect of the room is, inspired by this Steam Workshop mod.
 * Added a new option in the menu to display charge bars, based on this Steam Workshop mod.
 * Added 5 new Eden hairstyles, based on this Steam Workshop mod.

Booster Pack #
The second Booster Pack was released on May 12, 2017 on PC, and contains 6 new items, 1 new trinket, and miscellaneous changes.

Other Features

 * Angel Rooms were rebalanced - they contain more items but only a single one can be collected.
 * Mods no longer disable achievements after beating Mom once. This includes the use of the Debug Console.
 * Active items now charge during Challenge Room waves.
 * Multiple items that affect the appearance of bombs now stack visually, based on this Steam Workshop mod.
 * now changes appearance depending on how many flies are in the jar, based on this Steam Workshop mod.
 * Added Mom's Dressing Table, which changes Isaac's appearance to only reflect a few of his items, based on this Steam Workshop mod.
 * Added the Stompy transformation.

Booster Pack #
The third Booster Pack was released on June 30, 2017, for the PC, and contains 4 new items, and 1 trinket.

Other Features

 * Added new Eden hairstyles, based on this Steam Workshop mod.

Booster Pack #
The fourth Booster Pack was released on October 10, 2017 and contains 5 new items, 1 new trinket, and 6 new enemies.

Other Features

 * Most items from previous Booster Packs have new and improved graphics.
 * collectible sprite was changed.
 * collectible and costume sprites were changed.
 * collectible and familiar sprites were changed.
 * collectible and entity sprites were changed.
 * collectible and familiar sprites were changed. Familiar sprites were based on this Steam Workshop mod by Quartz.
 * collectible sprite was changed.
 * Hairpin trinket sprite was changed.
 * Butter! trinket sprite was changed.
 * Door Stop trinket sprite was changed.
 * Added 400 new rooms to better integrate the Afterbirth+ enemies (including Booster Pack #4 enemies) into the game.

Booster Pack #
The fifth and last Booster Pack was released on April 30, 2018 and contains 1 new character, 18 new items, 3 new trinkets, 7 new enemies, and a new boss.

Characters
The Forgotten is a new character added in the Booster pack.

Other features

 * Bone Hearts, a new heart-type.
 * Golden Bombs now have a pickup sound effect.
 * Black Hearts now have a pickup sound effect.
 * White Poop, a new poop type.
 * Gaping Maws supposedly have a chance to become Broken Gaping Maws, although this never actually happens ingame.
 * Changes to Greed mode Angel Rooms.
 * Added 817 new rooms.
 * New charge bar graphics.
 * New and improved graphics based on this Steam Workshop mod.
 * New and improved graphics for burrowing monsters based on this Steam Workshop mod.
 * Added the unlocks from the Switch version of the game.
 * Added 64 new achievements, including 36 from the Switch version.
 * Added 43 new Co-op Babies, 41 being cosmetic and two unlockables (Bone Baby and Bound Baby).

Trivia

 * Booster Pack 3 is the only booster pack to not be featured on a blog post.
 * The developers of Antibirth helped create booster packs 4 and 5.
 * Many of the added Co-op Babies from Booster Pack 5 are references to popular mods that were never added in the Booster Packs.