Sack Head

Sack Head is a passive item added in the Binding of Isaac: Afterbirth expansion.

Effects

 * All bomb, coin, key, card, rune, pill, and battery pickups have a high chance to be replaced with sacks.
 * This includes pickups spawned by anything: chests, slot machines, special shopkeepers, etc.

Synergies

 * Contract From Below: Doubles the sacks received after clearing a room.
 * D20: Sacks often contain batteries. The D20 rerolls opened sack items into batteries and more sacks. Rinse and repeat.
 * Flat Penny: When picking up a penny, a sack might drop instead of a key. The sack might contain more pennies which leads to more sacks.
 * Head Of The Keeper: Enemies hit by Isaac's tears have a chance of dropping sacks instead of coins.
 * Lucky Rock: Blown up rocks have a high chance of dropping sacks instead of pennies.
 * Safety Scissors + Curse Of The Tower: Each defused bomb has a chance to be replaced with a sack, so up to six sacks can spawn from taking damage.
 * Safety Scissors + Anarchist Cookbook: Each defused bomb has a chance to be replaced with a sack, so up to six sacks can spawn on use. In addition, sacks can spawn batteries, which allows this to be used multiple times.
 * Guppy's Tail: Chests often contain sacks, making most gold chests pay for themselves and then some.

Ingame Footage
Sack Head