Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.) Whenever Blind Zealot deals combat damage to a player, you may sacrifice it. If you do, destroy target creature that player controls.
Official Rulings for Blind Zealot
6/1/2011 : You'll choose the target creature when the ability goes on the stack. You'll choose whether or not to sacrifice Blind Zealot when the ability resolves.