Spawns a trapdoor that leads to the next floor upon activation. Unlocks The Forgotten when used on a mound of dirt that appears in The Dark Room.
Adds one soul heart and allows the breaking of rocksand damaging enemies by simply walking over them. Increases damage and decreases speed. All effects except for the Soul Heart wear off upon leaving the room.
Spawns a pile of poop where the character is standing and knocks nearby monsters back. May yield pickups like regular poop.
Upon use, deals one heart of damage to Isaac and grants +1.2 damage for the current room.
Hurts Isaac without depleting health, activating any items that trigger upon taking damage.
Upon use, spawns a sprinkler that rotates and fires tears.
Removes a heart container, increases damage and range, and grants a Cube of Meat.
Upon use, turns the character into a into a Pac-Man-like creature for 5 seconds, granting invulnerability, inflicting fear on all enemies, and replenishing half a red heart container for every two enemies killed.
Book of Revelations
Adds 1 soul heart, increases the chance for a Devilor Angel Room to appear, and increases the chance for the next boss to be a Horseman (except on XL floors and floors with fixed bosses such as Mom).
Spawns a penny and has a 50% chance to double all items and pickups in the room. If the effect fails, the items and pickups disappear.
Throws out a blue flame that can pass over gaps (but not through rocks). The flame damages anything in its path.
Sets a big red target on the ground (similar to the Epic Fetus item) which can be controlled with tear controls. After 6 seconds or by pressing space again, a huge explosive missile hits it, which damages all enemies caught in its blast radius.
Summons a random familiar for the current room. Can summon familiars not yet unlocked.
Head of Krampus
Fires a cross-patterned brimstone shot, just like The Fallen and Krampus shoot.
Freezes all enemies until a fire button is pressed.
Damages all enemies in the room, but deals a heart of damage to Isaac with each use.
Deploys a decoy Isaac that eventually explodes with an increased blast radius.