Min-Min

Min-Min is a boss added in The Binding of Isaac: Repentance that can appear in.

Phase 1
Min-Min floats slowly towards Isaac and performs the following attacks:
 * Spits a Willo at Isaac which fires a projectile at him before returning to orbit around Min-Min. Min-Min can have a maximum of 4 orbiting her.
 * This can be done multiple times in quick succession until the limit of 4 Willos has been reached.
 * Willos orbiting Min-Min occasionally fire a projectile towards Isaac.
 * Once Min-Min has 4 orbiting Willos, she periodically causes them to fire 3 projectiles outwards. If any Willos are killed during this attack the remaining ones perform this attack uninterrupted.

Phase 2
In this phase Min-Min removes the large corpse around herself, reducing her hitbox greatly. In addition, Min-Min can now have a maximum of 7 Willos orbiting her. She will continue to float slowly towards Isaac and has new attacks:
 * Min-Min spawns up to up to 4 Willos around herself and then causes all orbiting Willos to fire 3 projectiles outwards.
 * Willos orbiting Min-Min still occasionally fire a projectile towards Isaac.
 * Spits a Willo at Isaac which fires a projectile at him before returning to orbit around Min-Min.
 * Causes the current orbiting Willos to fire 3 projectiles outwards.
 * Sends her orbiting ring of Willos to chase Isaac. After a few seconds, they return.
 * Disappears and creates several groups of 1 to 5 lights on the ground. One group at a time, Willos appear from the lights, fire at Isaac, and disappear.

Upon Min-Min's defeat all spawned Willos die alongside her.

Trivia

 * Min-Min is confirmed to be female.
 * In her first phase, Min-Min is hiding within what appears to be a drowned and bleached corpse of The Husk.
 * In a way she can be seen as the posthumous version of Lil Blub.
 * Min-Min may be a reference to Min Min lights, a light phenomenon that has often been reported in outback Australia, where remote lights appear on the horizon.
 * Min-Min in her first phase is very similar to the Mullighoul monster as they both are white creatures, have a ball of light in the mouth, and shoot out Willos.
 * In the files of Repentance, there is an unused Boss Portrait for a Boss called "Maid In The Mist". Unlike the other unused Bosses, there are no files for this boss. This is likely because she was early concept for what would become Min-Min in the final game, as they are both female, share a Willo theme, and were both assigned the enemy ID 913 according to their file names.