Frost Walker

Oracle Text

When Frost Walker becomes the target of a spell or ability, sacrifice it.

Card Rulings

11/24/2014 If Frost Walker becomes the target of a spell or ability, its ability triggers and is put on the stack on top of that spell or ability. Frost Walker’s ability will resolve (causing it to be sacrificed) first. Unless the spell or ability has another target, it will be countered as it tries to resolve for having no legal targets.