Lurker
Lurkers are massive enemies encountered exclusively in the 
Corpse that are found inside of pits. They vary greatly in shape and size, and fill out most spaces within the pit that they spawn in; multiple Lurkers can spawn in a single pit.
Each Lurker is comprised of various chunks that each behave differently:
- Tissues act as the main body and simply connect other parts together inside the pit.
- Stomas are mouth openings that periodically spit out volleys of short-ranged blood and tooth projectiles towards Isaac, along with spawning a
Toma Chunk. - Teeth act as obstacles and block Isaac's tears. They can be destroyed by explosions and leave behind Tissues.
- Cores are the only part of the Lurker that can be damaged. They appear as the eyes of a Lurker.
- Stretches will cross over the ground, connecting Lurker parts that fill out separate pits, turning the two masses into one Lurker.
When all the Cores of a Lurker have been destroyed, the Lurker dies. Lurkers will usually leave behind pits upon death, but some Tissues and Tooth chunks can form bridges instead to allow Isaac to cross the pit.
Lurkers without any cores are completely invulnerable, and will die once the room is cleared.
Notes
- All aspects of a Lurker are predetermined and designed to fit each room layout.
- There is currently a maximum of 4 separate Lurkers per room.
Sulfuric Acid and 
Terra can destroy Lurker Teeth.- Lurkers are immune to the effect of
Meat Cleaver.
Trivia
- Some of Lurker's sound effects are taken from the Ravager from the game Minecraft.
- Lurker is considered the most iconic Morbus enemy by the Fiend Folio developers.
Gallery
A typical patch of Lurker Tissue.
A typical Lurker Core.
A typical Lurker Stoma.
A typical Lurker Tooth.
A typical Lurker Stretch.
