Item: Slipped Rib
Increases all stats and enlargens Isaac.
Halo of Flies
Spawns two pretty fly familiars that block enemy shots and deal contact damage to enemies.
Key Piece 2
Combined with Key Piece 1, unlocks the golden gate in the starting room of The Chest and Dark Room to fight Mega Satan.
Cube of Meat
Orbiting familiar that blocks enemy shots and deals damage to enemies. If collected while already having one, makes the familiar evolve. Only drops from Horsemen. Similar to Ball of Bandages.
A familiar that drops a Little Battery every 4 rooms. Has a small chance to freeze all enemies in the room when hit.
Circle of Protection
Surrounds Isaac with a large white halo around him that pulsates. With each pulse, the halo deals contact damage to enemies equal to Isaac's damage. Each pulse also converts any enemy shots touching the ring into friendly purple homing tears.
Increases speed and reduces character size. Also gives a random pill.
Reveals all special rooms (except secret rooms of any kind).
Randomly increases and decreases some of the character's stats. There will always be at least one stat increase and one decrease and the same stats can be increased/decreased multiple times.
The first enemy killed in a room explodes and poisons nearby enemies. Poisoned enemies will also explode upon death.
Spawns a friendly familiar leech on the ground that hunts down enemies and heals you for half a heart each time it eats one.
Spawns a familiar that drops random pills every 2 rooms cleared. Upon using a pill, all enemies in the room are poisoned.
Tears are replaced with laser rings that pierce through enemies and deal damage to enemies within them. Can be charged to increase the size of the ring.
Randomly while firing tears, Isaac will stop firing and turn red, where he will charge and release a lot of 'tears' in one go. In the burst of tears is a kidney stone which deals a lot of damage.
Crown of Light
Gives Isaac a crown that glows blue when active, and turns gray when inactive. While Isaac has no empty red heart containers, Isaac's tears are replaced with blue diamond tears that deal double damage. Regardless of health, the crown will deactivate for the current room when Isaac takes damage.
The Small Rock
Increases damage by 1, increases tears by 0.2, and decreases speed by 0.1.
Adds a chance to shoot a fire that damages enemies and remains in place until it deals enough damage or the room is left.