Witch

"Ladies... that ain't you, is it, girls? Well, do you hear that witch? I'm gonna give her something to cry about. Probably crowning her... burning her... or both."

--Su Ji-Hoon, Something Special to Be Infected

The Witch is a Special Infected that can instantly incapacitate, or even kill, a player if she's startled or attacked. She is also the only non-playable Special Infected.

In When the Cold Breeze Blows Away, they can also serve for the Undead Alliance as well.

Summary
The Witch is highly sensitive to light and the close presence of uninfected humans. Shining a flashlight on a Witch or approaching too closely will "startle" her and trigger an attack. Hitting her with any damage has the same result. She is completely unresponsive to Infected and the passage of nearby bullets.