From Team Fortress Wiki

“

— The Demoman lamenting his eye ...Everyone thinks I'm just a one-eyed bloody monster... ”

MONOCULUS is the RED Demoman's missing eye, haunted by the Bombinomicon. It was summoned by Merasmus when the RED Soldier broke his staff. In the Bombinomicon comic, it is depicted as a large brown floating eye that fires purple rocket-like eyeballs.

Behavior

MONOCULUS will spawn out of Eyeaduct's control point every 3 minutes (with a random variation of 30 seconds) when at least 10 players are on the server and assigned to a team. Standing on the Control point while MONOCULUS spawns will disintegrate the respective player. The players have 2 minutes to defeat it, or it will disappear. While MONOCULUS is alive, the point resets to neutral ownership and is unable to be captured, rendering the round temporarily unwinnable for either team. MONOCULUS's remaining health is displayed as a bar in a box near the top center of the screen. It fires eye-shaped projectiles that are guaranteed critical hits. When enraged, it shoots three of these projectiles in quick succession. Its projectiles can be deflected, similar to the Soldier's rockets.

At random intervals, it will teleport, leaving a swirling, purple vortex where it last was. The portals have attraction effects on nearby players to help players enter more effectively. Players are able to enter this vortex, and will be taken to the Underworld. Upon entering the Underworld, the player will spawn on an island and take continuous periodic damage. Another portal will be across from the player on another island. Upon exiting the Underworld, a player is spawned at one end of the map, invulnerable, crit boosted, overhealed to 200% their maximum health, and having a speed buff as if hit by the Disciplinary Action. Damaging MONOCULUS while in this state will stun it and cause it to sink to the ground for a few seconds and will start groaning.

Critical hits will anger MONOCULUS in a way that accelerates its rate of fire. In this mode, the eyeball projectiles' speed matches the Rocket Launcher's projectiles' speeds and MONOCULUS will flawlessly lead its targets until it calms itself. It is worth noting that MONOCULUS resists 50% of critical damage, resulting in critical hits dealing double damage as opposed to the usual triple damage. MONOCULUS also has a natural damage resistance against Miniguns and Flamethrowers. However, damage fall-off and ramp-up is completely ignored, meaning a successful hit will always deal the base damage of the corresponding weapon. Thrown weapons, such as Mad Milk, will bounce harmlessly off MONOCULUS. When MONOCULUS is angry, its iris changes from brown to a bright red colour as well as its skin which changes to a light brown.

Upon MONOCULUS's defeat, it will first change into a massive Jarate explosion, soaking any nearby players. An opened Bombinomicon will then spawn, surrounded by a red swirling vortex. This Bombinomicon will constantly point at the player who killed MONOCULUS, tilting and rotating to follow the player. Players who enter this will be teleported to Loot Island in the Underworld, at the base of a hill. On top of this hill is a large skull and a cage which contains the Bombinomicon. The cage will slowly descend into the ground where players can collect the Bombinomicon, awarding the "Dive into a Good Book" achievement. Some time after the book is available, a laugh will be heard, then the hill will be filled with exploding eyeball projectiles, killing any player still standing upon it, and the cage will cover the Bombinomicon again.

Defeating MONOCULUS automatically grants the "Optical Defusion" achievement, which gives the player the MONOCULUS! hat.

As of the November 2, 2011 Patch, MONOCULUS now has a level. Each time it is defeated, it will level up and receive higher health points. When MONOCULUS escapes, its level returns to 1. The maximum defined limit for MONOCULUS's level is 32,767.

Strategy

Related achievements

Optical Defusion

Kill MONOCULUS!

Foul Territory

Cause an environmental death by stunning or slowing an enemy. Fall Classic

Cause an environmental death or suicide using the Force-A-Nature's knockback.

Death From Below

Kill 10 opponents who are airborne with the Direct Hit.





Dead Heat

Kill an enemy in the same second that he kills you.





He Who Celt It

Use the Sticky Launcher to kill an enemy player via environmental damage.





Crock Block

Survive a direct hit from a critical rocket.





October 27, 2011 Patch (Very Scary Halloween Special)

Introduced MONOCULUS to the game.

October 28, 2011 Patch

Fixed a client crash that could occur while loading the map if MONOCULUS is killed or stunned.

[Undocumented] Fixed shooting MONOCULUS with bullet-firing weapons leaving the decals of impacted concrete.

November 2, 2011 Patch

MONOCULUS receives a faster firing rate and higher HP each time he respawns. This is indicated by levels.

September 4, 2012 Patch

Fixed Monoculus health bar not showing when Monoculus spawns.

November 2, 2012 Patch

Updated the health bar for Merasmus and Monoculus.

November 10, 2016 Patch

Updated the spawn/death sounds for Monoculus and Merasmus to remove the Horseless Headless Horsemann sound effects.

Bugs

If two players from different teams enter the Underworld portal at the same time, both may get stuck in mid air after teleporting. They get un-stuck if either player dies or commits suicide.

If MONOCULUS is not defeated and leaves, its health bar may persist on the HUD.

When MONOCULUS is active, the message telling players the point cannot be captured says "Waiting for teammate", which is incorrect.

Killing someone with a deflected eyeball projectile still counts as a MONOCULUS kill.

Being killed by standing on the control point when MONOCULUS emerges or from a pumpkin bomb detonated by its eyeball projectiles will be counted as a suicide/environmental death.

If a player hits one of the MONOCULUS projectiles with a Sandman's ball or Wrap Assassin's bauble, it will freeze the projectile in place.

The game will not log that a building is destroyed by MONOCULUS.

Trivia

Gallery

An angry MONOCULUS.

MONOCULUS' eyeball projectile.

MONOCULUS as it appears in the Bombinomicon comic.

Message that appears when MONOCULUS spawns.

Message that appears when MONOCULUS is defeated.

Message that appears when MONOCULUS leaves.

Message that appears when leveled MONOCULUS spawns.

Message that appears when leveled MONOCULUS is defeated.

Message that appears when leveled MONOCULUS leaves.