The Operator Symbol, the most recognizable symbol of the Slender Man Mythos, was first used in MarbleHornets and is the unofficial symbol of the series.


In regular entries:

  • Entry #8: as part of Alex's drawings.
  • Entry #11: as part of Alex's drawings hanging on the wall.
  • Entry #13: Alex finds an Operator symbol drawn on the ground.
  • Entry #21: on the side of the Red Tower.
  • Entry #23: on a white board hanging from a wall in The House.
  • Entry ######: in the beginning of the video.
  • Entry #26: at the end of the tape next to "HELP".
  • Entry #33: taking the place of a zero in the safe combination.
  • Entry #37: it flashes upon young Alex's face for a moment.
  • Entry #44: Alex draws this with the word "OPERATOR" underneath.
  • Entry #46: as part of Alex's drawings that Jay finds.
  • Entry #50: in drawings Jay finds in Alex's apartment. In one drawing two Operator symbols seem to represent eyes.
  • Entry #60.5: it's on one of the medical records that Jay has been looking over.

In totheark entries:

  • Version: at the very end.
  • Attention: as part of footage from the Red Tower.
  • Warning: drawn once, and then several times as a repeating motif.
  • Forecast: at 0:11, a head with two x's drawn through its eyes flashes briefly.
  • Intermission: briefly seen on one of the trees in the drawing, and at the end.
  • Memories: a grinning head with x's through eyes appears.
  • Inquiry: as a drawn symbol.
  • Reminder: It is seen for a moment at 0:10.