The Stain

The Stain is a boss added in The Binding of Isaac: Afterbirth that can appear:

In all environments of Chapter 2 ( Caves, Catacombs, Flooded Caves).
Only in Caves and the Flooded Caves.

Behavior[]

The Stain burrows underground when Isaac is not within range. While burrowed it becomes invincible and follows Isaac's movements. When close to Isaac, it pops out and performs one of the following attacks:

Sends out 2 patterns of numerous projectiles in all directions. The first barrage consists of fast-moving bullets that slow down. The second barrage consists of slow-moving bullets that speed up.
Sends out tendrils to its left and right leaving small puddles of damaging Red Creep directly around The Stain and to its either side.
Spawns 2 Chargers and can have a maximum of 3.

It will stay vulnerable for a brief moment after performing an attack before quickly burrowing underground again.

Champion Versions []

Grey: Continuously spawns 2 Round Worms instead of Chargers, with a maximum of 3 at any time. Never fires barrages of bullets.

Gallery[]

The Stain in-game.
The Stain performing its barrage attack.
Grey Champion Stain.
The Stain as one of Delirium's forms.

Arena[]

When fighting The Stain following obstacles can sometimes spawn:

2 red poops (near upper-right and bottom-left corners)
2 red poops (near the center)
4 red poops (in all corners)
2x2 Pits in upper-right and bottom-left corners

Trivia[]

It is the posthumous version of Polycephalus. It appears that the top heads have been stripped of their skin, while the bottom head only lacks its first skin layer.
- Unlike its alive counterpart, the lower head has closed eyes and eyelids.
The Stain has an alternative more degraded variation known as The Pile.
2 Stains can spawn for the nightmare wave for the 6th floor of Greed Mode.
A third head can be seen in the background in The Stain's boss art.
During the versus screen, The Stain's popping out sound can be heard. The Stain is one of seven bosses that can be heard in the versus screen; the other six are The Forsaken, Big Horn, Mom, Mom's Heart (pre-Repentance), It Lives (pre-Repentance), and Mother.
Prior to Booster Pack #5, The Stain could spawn Drowned Chargers if it was fought in the Flooded Caves. This also applied to Chub.

Bosses
Chapter 1	Gemini • Steven • Blighted Ovum • Dingle • The Duke of Flies • Famine • Gurglings • The Haunt • Larry Jr. • Monstro • Pin • Widow • The Fallen • The Headless Horseman Dangle • Little Horn • Rag Man • Turdlings Baby Plum
Chapter 1.5	Lil Blub • Wormwood • The Rainmaker • Min-Min • Clog • Colostomia • Turdlet
Chapter 2	Fistula • Chub • C.H.A.D. • Carrion Queen • Dark One • Gurdy • Gurdy Jr. • The Hollow • The Husk • Mega Fatty • Mega Maw • Peep • Pestilence • Polycephalus • The Wretched • The Fallen • The Headless Horseman The Forsaken • The Frail • The Stain Big Horn • Rag Mega Bumbino
Chapter 2.5	Reap Creep • Tuff Twins • Hornfel • Great Gideon • Singe • The Shell • The Pile
Chapter 3	The Adversary • The Bloat • The Cage • The Gate • Monstro II • Gish • Loki • Mask of Infamy • War • The Fallen • The Headless Horseman • Mom Brownie Sisters Vis Reap Creep • The Pile
Chapter 3.5	The Siren • The Heretic • The Visage • The Horny Boys • Mom • Mom's Heart
Chapter 4	Blastocyst • The Bloat • Conquest • Daddy Long Legs • Triachnid • Death • Lokii • Mama Gurdy • Mr. Fred • Scolex • Teratoma • The Fallen • The Headless Horseman • Mom's Heart • It Lives Sisters Vis • The Matriarch
???	Hush
Corpse	Chimera • The Scourge • Rotgut • Mother
Chapter 5	Satan • Isaac
Chapter 6	??? • The Lamb • Mega Satan
The Void	Delirium
Home	Dogma • The Beast • Ultra Death • Ultra Famine • Ultra Pestilence • Ultra War
Greed Mode	Ultra Greed Ultra Greedier

The Binding of Isaac: Rebirth
Achievements	Attributes	Bosses	Cards and Runes	Challenges	Chapters
Characters	Co-op	Items	Item pools	Monsters	Objects
Pickups	Pills	Rooms	Seeds	Transformations	Trinkets