You’ll immediately know if you’ve succeeded, as Mom will start yelling at you. You’ll need to defeat the boss of the first floor within one minute. Start a new run (it cannot be a seeded run) and get moving. You’ll have to have beaten the final boss of the game, The Lamb, at least once before you proceed, so don’t try to unlock The Forgotten before then.

This can be done on either Normal or Hard difficulty, so play on whichever you’re most comfortable with. To unlock The Forgotten, you’ll need to reunite the two halves of Mom’s Shovel. How The Forgotten fits into Binding of Isaac’s overall lore is still under debate, but we do know how players can unlock the skeletal creature. The club can either be swung as a melee weapon or charged up and thrown like a boomerang. A peculiar character, The Forgotten does not fire tears to harm enemies.

Hidden within Binding of Isaac: Rebirth’s Booster Pack #5 is a secret character known simply as The Forgotten.