How can I unlock Super Bandage?

Solution 1:

From The Binding of Isaac Wikia:

Increases HP by 1 and gives 2 soul hearts. Trivia: This is a reference to "Bandage Girl" from Super Meat Boy, another game Edmund McMillian worked on. Rarely Found in Boss Rooms.

Unlocked by killing four Horsemen in one playthrough, not just by collecting four Meat Cubes.

This can be pretty tricky given the random nature of the bosses. The four bosses you need to kill, like the quote says, are four Horsemen; War, Death, Famine, Pestilence or The Headless Horseman. Any combination of these will suffice. (credit to Mr Smooth for the Headless Horseman and combinations)

Sadly, encountering all four of them in a single playthrough is entirely random without the aid of The Book of Revelations, as mentioned by Timothy Roy.

Solution 2:

I believe you have to kill all four horsemen in one playthrough.

You can use 'The Book of Revelations', if you find it, to make a horseman appear instead of a normal boss, or you just have to be lucky.

The unofficial Wiki states that super Bandage is indeed 'Unlocked by killing four Horsemen in one playthrough, not just by collecting four Meat Cubes.'

Solution 3:

The Super Bandage is unlocked by killing four Horsemen bosses in one playthrough, as explained in the Wiki. Search (F3) for Super Bandage and you'll find the entry, I can't seem to link to it.

Rarely Found in Boss Rooms.

Unlocked by killing four Horsemen in one playthrough, not just by collecting four Meat Cubes.