Card name: Bone Splinters
Mana Cost: Color B
Converted Mana Cost: 1
Types: Sorcery
Card Text: As an additional cost to cast Bone Splinters, sacrifice a creature.

Destroy target creature.

Flavor Text: Vastly outnumbered, the Zendikari found creative ways to even the odds.
Expansion: DC Starter set
Rarity: Common

Bone Splinters
Card rulings (?)
2008-10-01 You could choose to target the creature you're going to sacrifice to pay for Bone Splinters. First you choose the target (at which time it's still on the battlefield), then you pay the costs (at which time you sacrifice it). The spell will be countered.
2013-04-15 You must sacrifice exactly one creature to cast this spell; you cannot cast it without sacrificing a creature, and you cannot sacrifice additional creatures.
2013-04-15 Players can only respond once this spell has been cast and all its costs have been paid. No one can try to destroy the creature you sacrificed to prevent you from casting this spell.