Kozilek's Sentinel [Battle for Zendikar]

Set: Battle for Zendikar Type: Creature — Eldrazi Drone Rarity: Common Cost: {1}{R} Devoid (This card has no color.)Whenever you cast a colorless spell, Kozilek's Sentinel gets +1/+0 until end of turn. It moves through the tunnels as slowly and surely as the shifting stones.