hush (the binding of isaac)

One of many superbosses in The Binding of Isaac. Unlocked by defeating Mom's Heart at least 10 times, he can only be accessed by defeating said Heart (or It Lives!) within 30 minutes of the current run. What follows is not just a fight with ???, but also a hidden second phase where he grows into a kaiju and fights Isaac with danmaku and various hordes of monsters.