In a world where death is always violent, cruel weapons are as common as rocks.

The Brothers' War Retro Artifacts

Bone Saw

Equipped creature gets +1/+0.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

"When metal instruments are scarce, a saw constructed from the subject's femur will suffice for a craniectomy."
—Ashnod, research notes

Once a simple tool, it—like everything else on Zendikar—has been turned into a weapon against the Eldrazi.