X-COM: Terror from the Deep introduced a chilling array of underwater enemies that challenged even the most experienced commanders. Set in a future where Earth is once again under threat, the game shifts from alien skies to the depths of the ocean. The enemy roster in Terror from the Deep is both diverse and deadly, with aquatic lifeforms, alien hybrids, and mechanical horrors. Each enemy type brings unique threats to your squad, requiring varied strategies and careful preparation. Understanding how each enemy functions, what their strengths are, and how they evolve as the game progresses is essential for surviving the underwater war.
Aquatoids
The Early Threat
Aquatoids are among the first enemies encountered in Terror from the Deep. They serve a similar role to Sectoids from the original X-COM: UFO Defense. Aquatoids are frail but accurate, often armed with Sonic Pistols and Sonic Cannons. Their psychic abilities appear later in the game, making them more dangerous than they initially seem.
Strengths and Weaknesses
- High accuracy with ranged weapons
- Early-game psi powers in veteran missions
- Low armor and health make them vulnerable to direct attacks
Dealing with Aquatoids effectively involves using cover and flanking maneuvers. Since their weapons can kill in one shot, positioning is crucial.
Gill Men
Primitive Yet Dangerous
Gill Men are a more resilient enemy type. These amphibious humanoids wield Sonic weapons and serve as a recurring threat in the mid-game. Though lacking in advanced technology, their toughness and aggression make them difficult to eliminate without sustained fire.
Battlefield Role
- Moderate armor and health
- No psi abilities, making them more predictable
- Often appear in port attacks and alien colonies
Gill Men are dangerous when grouped, and they tend to push forward rather than hide. Grenades and autofire weapons are effective counters.
Lobstermen
The Armored Nightmare
Lobstermen are some of the toughest enemies in Terror from the Deep. They appear relatively early and quickly become a persistent threat. Their heavy armor makes most conventional weapons nearly useless unless aimed precisely or using high-powered explosives.
Why They Are Feared
- Extremely high armor, especially on the front
- Often carry powerful melee weapons like Vibro Blades
- Psychic resistance is high, making them hard to control
To defeat Lobstermen, players should use Thermal Tazers for capture or Thermal Shok Launchers for lethal takedowns. Avoid close combat unless you have melee superiority.
Calcinites
Fast and Melee-Oriented
Calcinites are armored suits animated by alien technology. They specialize in melee attacks and can close distances rapidly, making them a threat to isolated units. Often found in alien base missions or ship terror missions, they serve to disrupt and surprise.
Combat Characteristics
- No ranged attacks only melee
- Moderate armor, particularly resilient to low-damage weapons
- Excellent movement speed underwater
Best countered with close-range firepower or stuns, Calcinites should be a priority target when spotted. Keep your squad grouped and cover each other’s backs.
Deep Ones
The Human Hybrid Horror
Deep Ones are terrifying hybrids that appear as a fusion of human and alien features. They often accompany Gill Men and are capable of ranged bio-electrical attacks. While physically weaker, they can surprise players due to their uncanny appearance and decent accuracy.
Role and Tactics
- Use of ranged energy-based attacks
- Lower durability but good for ambushes
- Occasionally appear in large groups
Taking out Deep Ones quickly prevents flanking. Their attacks can bypass standard armor, so moving cautiously and eliminating them first is a good rule.
Tentaculats
The Most Terrifying Enemy
Tentaculats are arguably the most feared enemies in X-COM: Terror from the Deep. These floating creatures are the underwater equivalent of Chryssalids from the first game. They use melee attacks to instantly convert soldiers into zombies, which then hatch into more Tentaculats.
Threat Assessment
- Very fast and can fly underwater
- One-hit kill and zombify ability
- Armored, hard to take down quickly
The best strategy is to kill them at range before they get close. Incendiary weapons and reaction fire can help reduce the threat. Never let them near an unarmored soldier.
Triscenes
The Alien War Beasts
Triscenes are massive, dinosaur-like creatures used by the aliens as shock units. Equipped with powerful ranged weapons, they also have a secondary melee attack that can destroy terrain and kill soldiers in a single hit. Their large size makes them easy targets, but also hard to kill.
Key Details
- Very high health and armor
- Powerful dual-mode offense (melee and ranged)
- Often act as bosses in large missions
Rocket launchers, Sonic Cannons, and well-placed explosives are required to bring down a Triscene. Avoid engaging it at close range unless absolutely necessary.
Tasoths
The Elite Infantry
Tasoths are late-game enemies that serve as the core of alien strike forces. With high psionic ability, advanced weapons, and strong armor, Tasoths resemble upgraded Aquatoids and require serious firepower to defeat.
Combat Summary
- Strong psi abilities that can panic or mind control troops
- Armed with high-tier Sonic weapons
- Often found in alien bases and final missions
Psi-resistant soldiers and the use of Mind Shields help counter their abilities. Focus fire is the key to overwhelming them before they can disrupt your formation.
Hallucinoids
The Bio-Energy Floaters
Hallucinoids are jellyfish-like entities that float through the battlefield, firing powerful electrical blasts. While not the most resilient, they have strong area control capabilities and can suppress your squad with constant fire.
Combat Behavior
- Float over terrain easily
- Use electrical ranged attacks
- Weak to concentrated firepower
Shotguns and close-range ambushes work well against Hallucinoids. Keeping your squad mobile and spread out reduces the damage they can inflict.
Bio-Drones
Small But Deadly
Bio-Drones are small robotic enemies that serve as scouts and support units. While they don’t hit as hard as other enemies, they often accompany tougher threats and harass your flanks. Their compact size makes them hard to spot in dense terrain.
Combat Tactics
- Fast and agile, with short-range weapons
- Can detonate on death, damaging nearby units
- Used to flush out or pin down squads
Target them with reaction fire and avoid clumping your units. They are more dangerous when ignored than when dealt with immediately.
The variety and deadliness of enemies in X-COM: Terror from the Deep create a constant challenge for players. From early encounters with Aquatoids to late-game confrontations with Tentaculats and Triscenes, every mission demands careful tactical planning and team composition. Learning each enemy’s behavior, strengths, and weaknesses is essential for success. As you progress through the game, adapting your strategy to new threats will determine whether humanity survives the alien invasion lurking in the depths. Mastering these enemies is not just about firepower it’s about outsmarting and outmaneuvering a superior alien force in their own territory.