Idk

Idk stands for 'Invisible Dick Killer'
This is when a killer has an invisible dick, giving them advantages to kill people.

They might use their cum cannons or piss launchers (You won't even see it cumming)

"Hey Joey, why don't you have a dick?"
"I'm glad you assed, because IM AN IDK!"
"You're an I don't know?"
"NO! IM AN INVISIBLE DICK KILLER, NOW DIE!!!!"