Blood Puppy

Blood Puppy is a passive item added in The Binding of Isaac: Repentance.

Effects

 * Spawns a familiar that chases nearby enemies and deals 2 contact damage to them per tick (4 per second).
 * After killing 15 enemies, Blood Puppy becomes angry, and changes in the following ways:
 * Deals 7.5 damage per tick instead of 2 (15 per second).
 * Charges at enemies that are aligned with it in the cardinal directions.
 * If Blood Puppy charges into a live bomb, it will get caught on its mouth, preventing it from moving until it explodes.
 * Drops a half red heart for every 10 enemies it kills.
 * Will also try to attack Isaac, dealing a half heart of contact damage to him.
 * Can be damaged by Isaac, returning it to normal after it takes enough damage. Blood Puppy has 20 health and 90 Armor (effective health is ~140-180).
 * After getting 25 more kills (40 total), the angry version evolves, gaining the following modifications:
 * Becomes much larger and deals 15 damage per tick instead of 7.5 (30 per second).
 * Destroys obstacles it runs into while charging.
 * Deals a full heart of damage to Isaac instead of half a heart.
 * Drops a full red heart after every 10 kills instead of a half red heart.
 * Has 50 health instead of 20 (effective health is ~400-500).

Interactions

 * : Only increases the size and damage of Blood Puppy during its first phase.
 * : Tames an angry Blood Puppy and spawns another temporary one.
 * While the camo effect is active, stages 2 and 3 of the Blood Puppy will not target Isaac, but will still target other enemies, making it safer for the player.
 * : Using Eraser on Blood Puppy while it's angry will permanently prevent it from advancing to the erased phase. Using it on phase two will prevent it from becoming angry altogether.
 * : If Blood Puppy is angry, splits it into two copies. One copy can level up and be tamed like normal, but the other cannot level up and dies instead of being tamed.
 * Using, , , or on an angry Blood Puppy will spawn the respective pickup and tame it.
 * Using on an angered Blood Puppy will instantly transform him into the tame state, being useful since you can pick up the ball again.

Seeds
YSJN V3XQ (Treasure Room adjacent to spawn)