Boss (Item Pool)

The Boss Pool is the pool of items that are dropped by bosses in the Boss Room, barring those with specific set item drops, and can be found in the Boss Challenge Room.

Name	ID	Weight	Description
The Belt	5.100.28	1	+0.3 speed.
Blood Clot	5.100.254	1	Tears fired from the left eye have +1 flat damage, +5 range, and +0.5 tear falling speed. Tears fired from the left eye have +1 flat damage and +2.75 range.
Blue Cap	5.100.342	1	Gives one full Red Heart container, +0.7 tears, and -0.16 shot speed. Heals 1 additional Red Heart.
Box	5.100.198	1	Spawns various pickups: 1 coin, 1 Key, 1 Bomb, 1 Heart, 1 card/rune, 1 pill and 1 trinket.
Breakfast	5.100.25	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
Caffeine Pill	5.100.340	1	Grants +0.3 speed, reduces Isaac's size, and gives a random pill.
Cat-o-nine-tails	5.100.165	1	+1 damage, +0.23 shot speed.
Dessert	5.100.24	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
Dinner	5.100.23	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
Experimental Treatment	5.100.240	1	Randomly increases and decreases some of Isaac's stats. Increases four random stats and decreases the other two.
Growth Hormones	5.100.70	1	+1 damage, +0.4 speed. +1 damage, +0.2 speed.
Jesus Juice	5.100.197	1	+0.5 damage, +0.25 range, +0.5 tear falling speed. +0.5 damage, +1.5 range.
Latch Key	5.100.343	1	Grants 1 Soul Heart and +1 luck. Spawns 2 Keys.
Lunch	5.100.22	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
MEAT!	5.100.193	1	Grants one full Red Heart container, +0.3 damage. Heals 1 additional Red Heart
Magic 8 Ball	5.100.194	1	+0.16 shot speed, spawns a random tarot card. Increases the chance of finding a Planetarium.
Magic Scab	5.100.253	1	Grants one full Red Heart container, +1 luck. Heals 1 additional Red Heart.
Match Book	5.100.344	1	Grants Isaac one Black Heart, spawns two or three Bombs. Also spawns Match Stick if it hasn't been encountered yet.
Mom's Coin Purse	5.100.195	1	Spawns 4 random pills near Isaac.
Mom's Heels	5.100.30	1	+5.25 range, +0.5 tear falling speed. +2.5 range, enemies that touch Isaac take 12 damage.
Mom's Lipstick	5.100.31	1	+5.25 range, +0.5 tear falling speed. +3.75 range. Spawns a Heart on pickup.
Mom's Underwear	5.100.29	1	+5.25 range, +0.5 tear falling speed. +2.5 range. Spawns 3-6 Blue Flies on pickup.
Old Bandage	5.100.219	1	Grants an empty Red Heart container. Adds a chance of dropping a Red Heart after taking damage.
Pageant Boy	5.100.141	1	Spawns seven random coins around Isaac.
Pentagram	5.100.51	1	+1 damage, increases Devil Room / Angel Room chance by 10%.
Placenta	5.100.218	1	Grants one full Red Heart container, and a chance to regenerate a Half Red Heart of health every minute of gameplay.
Roid Rage	5.100.14	1	+0.6 speed, +5.25 range, +0.5 tear falling speed. +0.3 speed, +2.5 range
Rotten Meat	5.100.26	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
Safety Pin	5.100.339	1	Grants one Black Heart, +5.25 range, +0.5 tear falling speed, +0.16 shot speed. Grants one Black Heart, +2.5 range, +0.16 shot speed.
Screw	5.100.255	1	+0.5 tears, +0.2 shot speed.
A Snack	5.100.346	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
Speed Ball	5.100.143	1	+0.3 speed, +0.2 shot speed.
Squeezy	5.100.196	1	+0.4 tears, spawns 2 Soul Hearts.
Stem Cells	5.100.176	1	Grants one full Red Heart container and +0.16 shot speed. Heals 1 additional Red Heart
Synthoil	5.100.345	1	+1 damage, +5.25 range, +0.5 tear falling speed. +1 damage, +2.5 range.
Tooth Picks	5.100.183	1	+0.7 tears, +0.16 shot speed.
Torn Photo	5.100.341	1	+0.7 tears, +0.16 shot speed.
Wire Coat Hanger	5.100.32	1	+0.7 tears.
Wooden Spoon	5.100.27	1	+0.3 speed.
Super Bandage	5.100.92	1 0.5	Grants one full Red Heart container and 2 Soul Hearts.
<3	5.100.15	1	Grants Isaac one Red Heart container and fully restores Isaac's health.
The Halo	5.100.101	1	Grants one full Red Heart container, +0.3 damage, +0.2 tears, +0.25 range, +0.3 speed, and +0.5 tear falling speed. Grants one full Red Heart container, +0.3 damage, +0.2 tears, +1.5 range, and +0.3 speed. Heals 1 additional Red Heart.
Little Steven	5.100.100	1	Spawns a familiar who follows Isaac around and fires homing tears.
Magic Mushroom	5.100.12	1	Makes Isaac bigger. Adds one Red Heart Container, +0.3 Damage, x1.5 damage multiplier, +5.25 Range, +0.3 Speed, and restores all Health. Makes Isaac bigger. Adds one Red Heart Container, +0.3 Damage, x1.5 damage multiplier, +2.5 Range, +0.3 Speed, and restores all Health.
Binky	5.100.438	1	Grants one Soul Heart, +0.75 tears and decreases Isaac's size.
Crack Jacks	5.100.354	1	Grants one full Red Heart container and drops a random trinket. Heals 1 additional Red Heart.
Mom's Pearls	5.100.355	1	+1.25 range, +0.5 tear falling speed, +1 luck. +2.5 range, +1 luck. Grants one Soul Heart.
Mr. Dolly	5.100.370	1	+0.7 tears, +5.25 range, +0.5 tear falling speed, Spawns a combination of 3 Red Hearts, Soul Hearts or Black Hearts on the floor when picked up. +0.7 tears, +2.5 range, spawns 3 random types of Hearts on the floor when picked up.
PJs	5.100.428	1 0.5	Grants 4 Soul Hearts and fully restores Isaac's health.
Dad's Lost Coin	5.100.455	1	+1.5 range, +1 tear falling speed. Drops a Lucky Penny. +2.5 range. Drops a Lucky Penny.
Divorce Papers	5.100.547	1	Grants one Bone Heart, +0.7 tears, spawns a Mysterious Paper.
Marbles	5.100.538	1	Spawns 3 random trinkets. Taking damage has a 5% chance to swallow Isaac's currently held trinket, gaining its effect permanently.
Marrow	5.100.541	1	Grants one Bone Heart and spawns three Red Hearts.
Midnight Snack	5.100.456	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
Belly Button	5.100.458	1	Drops a random trinket. Grants a second trinket slot.
Polydactyly	5.100.454	1	Allows Isaac to carry two cards, pills, or any combination of both. Spawns one random card, rune, or pill.
A Bar of Soap	5.100.564	1	+0.5 Tears, +0.2 Shot Speed.
Booster Pack	5.100.624	1	Drops 5 random cards.
Consolation Prize	5.100.644	1	Increases Isaac's lowest stat and drops either 3 Coins, 1 Bomb, or 1 Key depending on what Isaac has the least of.
Eye Drops	5.100.600	1	Increases the fire rate in Isaac's left eye, causing his eyes to fire at different rates.
Glass Eye	5.100.730	1	+0.75 damage, +1 luck.
Stapler	5.100.708	1	+1 Damage. Prevents Isaac from firing tears from his left eye, like Cain.
Stye	5.100.731	1	Tears fired from Isaac's right eye have +28% Damage, +6.5 Range, and -0.3 Shot Speed.
Supper	5.100.707	1	Grants one full Red Heart container. Heals 1 additional Red Heart.
Tropicamide	5.100.659	1	+2.5 Range, Increases tear size.

Trivia

This item pool only has passive items.
- The only other room based item pool that has this property is the Planetarium pool.
All items in this pool will increase stats, increase health, grant pickups, grant trinkets, or some combination of the four.
Some bosses will drop specific items that are not within the Boss Room pool, Steven, C.H.A.D., and Gish, giving Little Steven, Little C.H.A.D., and Little Gish respectively. These bosses are all references to previous games made by Edmund McMillen.
- Mom will drop a regular boss item, unless The Polaroid and The Negative have been unlocked, after which she will always drop those items.
- The Harbingers will drop either Cube of Meat, Ball of Bandages, A Pony, or White Pony, depending on the horseman encountered.
- The Fallen will always drop an item from the Devil Room item pool.
- Baby Plum will replace her regular boss drop with Plum Flute if she was spared.
- There's a 1% chance for some bosses to drop their thematic items, which can also be an active item such as The Poop that can drop from Dingle or Book of the Dead from The Forsaken.