He killed a White Walker.
Game of Thrones Season 6, Episode 6
She survived a White
Walker, for fuck's sake.
Game of Thrones Season 4, Episode 8
how in seven hells
did you manage to kill a White Walker?
Game of Thrones Season 4, Episode 9
One of the tennis balls
came off his WALKER
The Big Bang Theory Season 7, Episode 14
used one of these daggers to kill a Walker.
Game of Thrones Season 5, Episode 8