used one of these daggers to kill a Walker.
Game of Thrones Season 5, Episode 8
He killed a White Walker.
Game of Thrones Season 6, Episode 6
The Walker came for my baby.
Game of Thrones Season 3, Episode 10
One of the tennis balls
came off his WALKER
The Big Bang Theory Season 7, Episode 14
Why would obsidian kill a Walker?
Game of Thrones Season 5, Episode 5