The Matriarch is a new boss added in Booster Pack #5 that can appear in all environments of Chapter 4.
- Will jump and launch 8 Chubber shots in all directions, which will rebound back to herself.
- The Matriarch's hitbox is large enough that Isaac can shoot her from the sides and be out of this attack's range.
- Periodically spawns Fistuloids, and can have up to a maximum of 4 out at once. One Fistuloid will chase Isaac, while the rest will orbit the Matriarch.
- If the Fistuloid that chases Isaac is killed, one of the remaining ones will stop orbiting the Matriarch and will start chasing Isaac.
- Spawns two small Fistulas once it takes 140 damage, and 2 more every 100 damage afterward.
- Spews a blood shot that leaves Red Creep on the ground, similar to Mr. Fred. This shot can damage and bounce off of Fistuloids she has spawned.
- After taking 340 damage, the Matriarch will spawn a wave of glowing Red Fistuloids that have 20 HP and rapidly lose health, making them shoot their maggots almost immediately. After that, the Matriarch can use this attack just like any of her other attacks.
- If there are any orbiting Fistuloids while The Matriarch is doing this attack, they will start glowing Red and die as well.
- When at low HP (after taking ~540 damage), The Matriarch will split into a medium-sized Fistula, 2 small Fistulas, a Fistuloid, and a low-health version of Chub, the latter being similar to how Brownie leaves a weakened Dangle upon death. Any Fistuloids that were orbiting the Matriarch will now orbit Chub. This Chub never appears as a Champion.
- The Chub spawned from the Matriarch will always start charging in a random direction, regardless of Isaac's position before returning to the normal Chub pattern, similar to the Chargers spawned by Sloth.
- Also, if the Chub that is spawned from the Matriarch eats a bomb, she will spit it back out at the player. Most bomb modifiers will still be on the bomb, except for Bomber Boy.
The Matriarch as one of Delirium's forms.
Concept art for the Matriarch by _Kilburn.
- The Matriarch appears to be a Chub stuck inside a Fistula. In this way, it also acts as a giant Fistuloid.
- The Matriarch is the only boss added in a booster pack.