Nightmare

The Nightmare is a hostile Typhon encountered on Talos I during Prey (2017) and on Pytheas during Prey: Mooncrash.

Overview
The Nightmare is the biggest, strongest and most dangerous of all the Typhon aside from the Apex Typhon. Created by the Typhon ecology specifically to neutralize Morgan Yu, the Nightmare is highly aggressive and relentless in its pursuit. The Nightmare will begin tracking the player after they first enter the Arboretum through the G.U.T.S., and will appear at random throughout the game. The Nightmare will appear more frequently and suddenly if the player installs multiple Typhon abilities. Killing the Nightmare will cause it to respawn 30 minutes later, whereas running away and exhausting the timer will cause it to respawn 20 minutes later. The Nightmare will drop 30 Typhon Organs and 1 Typhon Cortex every time it is killed. The latter requires Necropsy in order to take.

Spawn Conditions

 * Exiting Crew Quarters and into the place where you enter deep storage
 * Going into Crew Quarters.
 * After Morgan goes to Deep Storage.
 * After spending enough Neuromod points on multiple Typhon skills at once.
 * It can also start its hunt after you gain access to the lift in the lobby, even if you have no Typhon skills whatsoever. The circumstances it can do such are currently unknown but may be linked to total Neuromods used.
 * In the Neuromod Division, After resetting the Neuromod's license during the Copy Protection side quest or if the player already has more than 20 Neuromods (after Patch 1.04, only occurs if Typhon skills have been purchased).

The first sign of the Nightmare's arrival is a brief shake of the station, followed by a loud roar produced by the creature itself. This is not a guarantee, as the Nightmare can spawn in another area you have just entered and your only warning will be by spotting it. Each time the Nightmare has spawned, you will have three minutes to evade or kill it before the timer runs out and it despawns. January will sometimes warn you when Nightmare makes its first appearance, unless January has already been destroyed prior to this. If the player has recently installed Typhon neuromods, January will point to that as the reason for Nightmare's presence. After Nightmare has been evaded or eliminated, January will then mention a prototype satellite used in Psychotronics, beginning the Mixed Signals quest (Although this can be done before January gives you the quest).

Nightmare's aggression depends on the number of Typhon skills you have - if you have no Typhon abilities, it will not spawn midway through an area, and will instead wait until you transition to an area where it can spawn before doing so. On the other hand, if you've invested in multiple Typhon abilities, it may be inclined to suddenly appear while you're already deep in an area. Its related timer will also activate immediately.

In Prey: Mooncrash, Nightmares will also spawn on Pytheas after Peter has progressed enough in his job. Unlike the Nightmares encountered on Talos I, these Nightmares will permanently roam the base until they are destroyed, having no time limit to disappear. There is also a Nightmare locked in a containment unit in Pytheas Labs, which cannot be released but can be scanned with a Psychoscope.

Design
Nightmares look like a bulkier version of a Phantom. Like almost all Typhon, it is a mass of tentacles and shifting matter. They possess six white spots that can merge into one, which serve as makeshift eyes. The Nightmare's "head" is actually, in fact, four to six mandibles that have conjoined to form the shape; These mandibles will split apart and spread out when it unleashes its main attack, accompanied by a roar. It is capable of squeezing through doorways, and appears to only take a humanoid shape for combat purposes.

Quests

 * The Nightmare is Hunting you (Repeatable, 3 minutes time limit)
 * Mixed Signals (Limited use up to 4 times once satellite has been repaired) Can attract and repel Nightmare when completed.

Strategy

 * You can usually tell if Nightmare is present, as it will have a nearly-full detection meter at all times, even if you've only just entered the area.
 * Hide until the Nightmare's associated side quest time is exhausted.
 * Gloo can work for a duration currently thought to be under 10 seconds. Useful for scanning more than offence.
 * Chaining several recycler grenades seems to be the safest method for a kill.
 * Circle strafing with a shotgun can often result in a quick kill, especially when fully-upgraded with Firearms I and II.
 * If possible, mimic a turret or operator. Your own health bar is immune to damage while mimicking an object, although the object can break and force you back out of morph matter.
 * It is a good idea to always save Shotgun Shells exclusively for Nightmare, as these are very effective. If you're running low, use another weapon to deal with other Typhon, or fabricate some more. Always be prepared for Nightmare when the hunt is on.
 * If lucky it will spawn in as you are getting on or off the elevator. At that point you are safe from its attacks and can wait out the hunt in the elevator.
 * Turrets are often not very effective, but in certain areas the Nightmare can be trapped within firing range yet unable to hit the turrets, resulting in a guaranteed (if slow) kill. A good example of this is the entrance to Crew Quarters in the Arboretum. The Arboretum has a large number of turrets dotted around. Fix the broken ones if you have the proper repair skill and reposition all the turrets in the doorway between the security station and storage room (You will need to either save Rani Chaudhary to access some of them, or alternatively hack the keypad to the related room where they're kept). This position will prevent Nightmare fighting them effectively, and the high number of turrets will rapidly drain its health.
 * Nightmare is vulnerable to psi abilities. Four uses of fully upgraded Psychoshock is enough to kill it.
 * The Nightmare is also susceptible to Mindjack, which will allow the player to escape and hide, while also making the powerful Nightmare sweep the area for other Typhon that often accompany it. Alternatively, mindjacking an accompanying Typhon will distract Nightmare and allow you to do damage to it.
 * If possible, mindjack a Telepath - their means of attack all have psi-nullifying abilities, which will disable Nightmare's homing orb attack. Furthermore, they themselves are airborne, and so they can remain out of reach of its melee attacks. In the right circumstances, a Telepath could possibly defeat Nightmare, alone.
 * A Weaver or a Technopath is an alternative choice, as the Weaver's shield can repel Nightmare, while generating Cystoids to attack it, and the Technopath can generate electrical nodes that damage Nightmare over time, as well as get turrets in a better position to attack Nightmare. They can both also be airborne and avoid melee attacks. However, they'd both also be very susceptible to Nightmare's homing orb attack.
 * If possible barricade a doorway with large items using the leverage ability, keeping yourself out of its melee range and blocking its energy balls. Even better is find a door with a "manual lockdown" button beside it, such as most of the offices in-game.
 * The Side Quest will not start until Nightmare is alerted of your presence. If you find Nightmare patrolling and doing nothing, the Side Quest will not start. Sneak away from it to avoid triggering the side quest, because when it is alerted the countdown will start.
 * The Nightmare will disappear once the timer goes out regardless of any remaining HP it has, so it is necessary to kill the Nightmare before the timer runs out, if you intend to fight it.
 * If Nightmare spawns where Dahl's Military Operators are everywhere (Shuttle Bay or Arboretum), the Military Operators and Nightmare will take each other out. Military Operators engage Typhon as well as human targets, and also Typhon see them as enemies.
 * If you complete "You rang?" Achievement or the "Mixed Signals" optional objective, you will be able to evade Nightmare every time it spawns by playing the TranScribe "Satellite Signal: Repel Nightmare".
 * The Nightmare will not fit into tight spots such as under a table and any tight passages (such as maintenance tunnels).
 * Phantom Shift is a good way of distracting Nightmare while allowing you to get some heavy damage in on it. Just be ready to move when your duplicate fades.
 * Nightmare is incapable of moving to higher levels if there are no stairs. The upper floor in Neuromod Division is an example of this case. Use this to your advantage to keep out of range of it while peppering it with your pistol or Q-Beam.
 * The Q-beam is an effective weapon if you can hide in a place where you can reach the Nightmare but it can't reach you.
 * Jumping and using the propulsion system can temporarily offset the movement penalty while using the Q-Beam or GLOO Cannon.
 * The Nightmare (like other walking enemies) will not spawn in zero-gravity environments such as the Talos-1 Exterior or the G.U.T.S.
 * This can be utilized if the player finds themselves chased by a Nightmare in the reactor chamber, as resetting gravity will kill walking enemies (since they are not programmed to combat in zero-g).
 * Best way to kill him if you have the correct neuromods installed is to - Hit him with Psychoshock III then hit him with Kinetic Blast III then finish him off with your weapon of choice. (preferably shotgun or Q-beam)
 * A Shotgun with maximized damage output, at least one increment in magazine capacity, as well as maximum sneak attack damage and security weapon damage boost is crippling to Nightmare, if you can surprise it. If it's coming your way, hide behind a corner until it appears, then fire when it comes into view. Lean out if necessary. If done right, it is possible to down Nightmare in just 5 Shotgun blasts.
 * The Golden Gun upgraded to maximum damage and range (Or at least a significant amount of range) can deal heavy damage from afar, which is best if getting close is too risky or not possible from your current position. With maximum magazine size as well, it's possible to down Nightmare with a single magazine.
 * Nightmare's main attack is a trio of homing orbs. These do a lot of damage and have blast radius. However, the homing ability is very loose, so putting an object in their way will stop them.
 * If you are in a safe place where the nightmare can only hit you with its orbs, and there is another typhon in the room, you are able to move yourself so the nightmare hits the other typhon with its orbs. When this happens, it can most likely 4-shot a Voltaic Phantom. Any clarification on this will be accepted.
 * Try to hack any Corrupted Operators that appear in each area. They will either distract Nightmare while you attack, or weaken it in time for when you encounter it. The same applies to turrets.
 * If using turrets to get an early advantage, try to space them out a bit, but still covering the same general area. Nightmare's attacks have damaging AoEs (Areas of Effect) that will bowl them over like skittles if they're all clumped up.
 * If you're trying to keep the security forces in Cargo Bay alive for the ending, keep away from there if you haven't seen Nightmare in a while, as if it spawns, it will usually be right on top of them and it will usually wipe the entire team out while barely taking any damage. This can include it killing Sarah Elazar too, and as such, can possibly impact the ending.
 * The Nightmare's melee attacks are extremely devastating - they can either completely ruin your health, or one-hit you, depending on how well the attack lands. It's a good idea to have the Last Chance Suit Chip active to lessen the chance of this happening, as every 5 seconds, it can allow you to endure what would otherwise be a fatal hit.
 * The Last Chance Suit Chip is not a randomly generated chip. It is instead given after saving Mikhaila Ilyushin, and then meeting her at your office later. This can be done at any time after receiving the General Access Card from January.

Trivia

 * The Nightmare is reminiscent of the Nemesis monster from Resident Evil 3 - They are both biological weapons whose existence is based solely on stopping the protagonist. They both can also be evaded or "killed" but will always come back again later to try and kill the protagonist again.
 * The Nightmare was likely named due to its purpose is to specifically hunt the protagonist. The player can either avoid it or kill it. Regardless, it will eventually come back later, therefore being Morgan's Nightmare.
 * The Nightmare's associated side quest is the only side quest in the game that can be repeated many times. When it respawns and notices your presence, the countdown timer and side quest will start.