Epic Fetus: Each explosion shoots 10 knives in a circle from the point of impact.

Picking up more than 16 knives won't fire more knives but will still modify the angle at which they're shot.

Diplopia/ Crooked Penny: Each additional copy of the item will grant an extra knife that fires slightly diagonally from the original one, up to a maximum of 16.

C Section: Fetuses hold small knives that spin around them slowly, causing extra damage.

Cricket's Body: The knife creates smaller tears when in contact with an enemy.

Compound Fracture: The knife creates bone shards while in contact with an enemy.

The brimstone-knives do not benefit from A Lump of Coal. This effect does not work with Azazel's default mini brimstone. The longer the charge, the more knives are added.

Brimstone / Sulfur: Shooting the knife also shoots a barrage of knives that goes across the screen, with each knife doing 80% ( 2x) of Isaac's damage the extra knives do not return.

Apple!/ Tough Love: The knife deals increased damage sometimes based on luck.

20/20 / Conjoined / The Inner Eye / Mutant Spider: Isaac holds only one, but shoots multiple knives at their typical spread.

The knife will not work in challenges with the blindfolded effect.

The knife can be fired in any direction if using mouse controls (enabled in options.ini).

The knife can be held and fired diagonally as if Isaac was holding Analog Stick.

This can be done easily with a controller's analog stick or with Analog Stick.

The knife can be held and fired diagonally with frame perfect input.

Collecting three items from this set will transform Isaac into his mother. This item belongs to the Yes Mother? set.Further charging only increases its maximum range.

The knife damage quickly drops to 2x Isaac's damage when returning regardless of charge state. The knife deals 2x Isaac's damage when held and 6x damage at about 1/3 of full charge.

Damage dealt by the knife depends on its charge state.The knife deals 2x Isaac's damage while held and 6x damage at the furthest possible point of its throw distance, regardless of the actual maximum range stat.The knife deals damage 20 times per second upon contact with enemies while Isaac is holding it.Holding down the fire button increases its range and power. Isaac's tears are replaced by a knife that pierces enemies and can travel through obstacles.

Libra scale drawing