Bubble
Bubbles are a unique type of hazard found exclusively in the 
Flooded Caves. They can be produced by a variety of Flooded Caves' monsters as a form of attack, but may also be found placed inside of room layouts on their own.
Bubbles come in four different sizes — Tiny, Small, Medium, and Large — and will constantly float in the air over obstacles, bouncing off of walls and having a very low amount of friction. Bubbles will deal damage to Isaac if they make contact with him, and will pop after taking any amount of damage, after touching Isaac, after the room is cleared, or once all 
Pressure Plates in the room are pressed.
Notes
- Bubbles that are placed in a room layout will be stationary.
- Bubbles can be pushed around by effects that cause knockback, such as
Butter Bean farts. - Bubbles have a unique appearance in
Scarred Womb, typically only seen when they are spawned by 
Monsoon.
Variants
Watery Bubble
Watery Bubbles act like regular Bubbles but come in only Small, Medium, and Large sizes, and will release projectiles after popping. The amount of projectiles is based on the bubble's size:
- Small Watery Bubbles will release a single projectile directly towards Isaac.
- Medium Watery Bubbles will release 4 projectiles in the cardinal directions.
- Large Watery Bubbles will release 8 projectiles in the cardinal and ordinal directions.
They are primarily spawned by 
Globulons and 
Geysers but can also be found in various room layouts on their own.
Explosive Bubble
Explosive Bubbles are bubbles that are always Medium-sized. They create an explosion when they are popped, which only deals 10 damage to enemies hit by it.
They are primarily spawned by 
Warties, which are also immune to explosions caused by other Explosive Bubbles.
Fly Bubble
Fly Bubbles are Large-sized bubbles that release an 
Attack Fly when they are popped.
They are primarily spawned by 
Cisterns but can also be found in various room layouts on their own.
Spider Bubble
Spider Bubbles are Large-sized bubbles that release a 
Spider when they are popped.
They are primarily spawned by Cisterns but can also be found in various room layouts on their own.
Isopoly Bubble
Isopoly Bubbles are Large-sized bubbles that release an 
Isopoly when they are popped.
Isopoly Bubbles are the only Bubble variant that can't spawned by any enemy and can only be found on their own in various room layouts.
Gallery
The appearance of Bubbles in the Scarred Womb.
The appearance of Watery Bubbles in the Scarred Womb.
