Rocks

Blocks movement and projectiles unless the player has flight or spectral tears respectively.
Can be destroyed with explosions and certain items like the Notched Axe, The Nail, Leo, or Thunder Thighs.
Can fill in a 1-block wide gap when pushed in the right direction by an explosion, or with one of the abilities that allows destruction by walking onto the rock.
- Note: With these items, it is important to walk in the direction of the gap.
Small chance to reveal a Crawl Space when destroyed.
Destroying 100 rocks will unlock the Lucky Rock trinket.

Tinted Rocks[]

Sometimes referred to as "Marked Rocks", they are always marked with an "x", and in some levels slightly tinted/discolored. These rocks are much less noticeable in Womb, Utero and Scarred Womb due to them being the same color as the surrounding rocks, but can still be distinguished by the "x" on the bottom right. Only one tinted rock can spawn per room.

Destroying 10 Tinted Rocks will unlock Mr. Mega.
Destroying 100 Tinted Rocks will unlock The Small Rock.
Multiple tinted rocks can spawn in one room by using XVI - The Tower?

Found in: Every Stage

Tinted Rocks have a chance to spawn 1-3 of the following when destroyed:

Soul Hearts
Keys
Bombs
Locked Chests (only one)
Normal Chests (only one)
Tinted Rock Spiders ( Mines and Ashpit only)
A combination of any of the items mentioned above
The Small Rock (after it has been unlocked)
- Not picking up The Small Rock right after it spawned doesn't prevent other tinted rocks from spawning it again. Even though the chances are very small, you can exploit this to obtain multiple Small Rocks.

Super Special Rocks []

Super Special Rocks are Tinted Rock variants whose smaller marks and lack of discoloration make them much harder to spot. Super Special Rocks take two bombs to blow up and drop the contents of two Tinted Rocks, with the exception that a single chest or The Small Rock appear without extra rewards.

The first super special rock encountered will always spawn The Small Rock, if it hasn't already been generated.

Only one super special rock can spawn per room, and normal tinted rocks cannot appear in the same room.

In Chapter 4 and Chapter 4.5 Super Special Rocks are almost identical to Tinted Rocks, making them easier to spot in these chapters.

Super Special Rocks are unlocked by Get a 5-win streak ( 3-win streak), using a different character each time.

Regardless of DLC version, an unlocking streak must be done with unique characters. That means each successful run must be performed with a new character for it to qualify.

Bomb Rocks[]

Act like rocks.

Found in: Low chance of replacing any rock.

Bomb rocks can be found anywhere a normal rock can spawn. They can only be destroyed by explosions and "stompy" items, like normal rocks. When they are destroyed, they create an explosion. Note that destroying a bomb rock next to a hole does not create a bridge as with normal rocks.

Spiked Rocks []

Spiked Rocks are variants of normal rocks which hurt Isaac on contact, even if he's flying. They can fill in a 1-block wide gap like ordinary rocks, but the spikes will remain and Isaac will take damage as he steps on them. If they are located in a room with Silver Buttons, after all are pressed, the spikes will retract into the interiors of the rock. If a Crawl space is generated with the same rock used to fill a gap, the bridge will not be spiked.

Flat File will remove the spikes from the rocks.

If spiked rocks are crushed by being Stompy, having Leo or Thunder Thighs, or using The Nail, they do not always deal damage, depending on Isaac's speed, size and the angle touched from.

Found in:

Fool's Gold Rocks []

Act like rocks. They have a small chance of replacing normal rocks, sometimes in small clusters, once unlocked.

Unlocked by: Defeat Mega Satan as Tainted Lilith

Fool's Gold Rocks have a chance to spawn the following when destroyed:

2-4 Pennies

Urns[]

Act like rocks.

Found in:

Shop
Arcade

??? (visual appearance of blue Polyps)
Angel Room

Urns have a chance to spawn the following when destroyed:

1-3 Spiders
A few Pennies
A Quarter (1% chance)
Swallowed Penny

Notes[]

If spiders spawn from destroying an urn after clearing a room, they will disappear if Isaac leaves and re-enters the room.

Mushrooms[]

Act like rocks.

Found in:

Mushrooms have a chance to spawn the following when destroyed:

Pills
Poisonous gas, which knocks back Isaac and deals a half-heart damage. (This does not count as an explosion.)
Liberty Cap
Magic Mushroom (0.5% chance)
Mini Mush (0.5% chance)

Skulls[]

Act like rocks.

Found in:

Skulls have a chance to spawn the following when destroyed:

Host enemies
Tarot cards
Black Hearts
Runes
Dry Baby (0.5% chance)
Ghost Baby (0.5% chance)

Notes[]

Prior to Booster Pack #5, skulls had a chance of spawning Mushrooms instead of Hosts.

Marked Skulls []

If A Strange Door is unlocked, a skull marked with a small "x" will appear in Depths II or XL. When destroyed, it will drop 0 - The Fool.
- If the player has Little Baggy, it will drop an identified Telepill.
- May also appear in Red Rooms, even if the player is not in Depths II or XL.
The Marked Skull has a different appearance when spawned on other floors, e.g. manually via the console or during the DELETE THIS challenge.
- For example, it will appear as a white urn in Basement, as a red mushroom in Caves or a horizontally flipped polyp in Womb.
- It will spawn as a regular bucket in Dross with no visual difference.

Polyps[]

Act like rocks.

Found in:

Womb
Utero

Polyps have a chance to spawn the following when destroyed:

6 red tears in all directions and a puddle of bloody creep
Blood Clot (0.5% chance)
Placenta (0.5% chance)
Umbilical Cord
Heart pickups

Buckets []

Act like rocks.

Found in:

Buckets have a chance to spawn the following when destroyed:

A burst of tears falling down in a small radius (Only full buckets)
1-3 Striders
1-3 Small Leeches
A few Pennies
Leech
Swallowed Penny

Buckets in Dross additionally have a chance to spawn the following when destroyed:

Notes[]

A Bucket that has water in it and is blown up/thrown by a Polty will cause a geyser of water that can hurt Isaac.
If a bucket would normally spawn striders, but is in a dry room, normal Spiders will spawn instead.