Every enemy in Casualties: Unknown, its layer, attack pattern and drops, plus the Elder Thornback fight and the traps that kill more players than monsters.
Casualties: Unknown Enemies: Every Threat and How to Fight It
Casualties: Unknown has three enemy families: spiders, humanoids and fixed plants. That is a small roster by survival-game standards, and it is deliberate. Each enemy is a different problem — infection, bleeding, dismemberment or a trap you walked into — and the cave layers arrange them into pressure.
This page lists what spawns where, how each one attacks, and the fight you should refuse.
Official source: Casualties: Unknown on Steam ↗
Enemy families
Spiders
| Enemy | Layers | Threat |
|---|---|---|
| Cave tick | 2, 5 | Small, fast, infection bite |
| Overgrown tick | 5 | Larger tick, more damage |
| Sand stalker | 3, 5 | Ambush predator in sand |
| Shade crawler | 1–5 | Common hunter in dark caves |
| Snow strider | 6 | Cold-layer predator |
| Thornback | 5 | Armoured, heavy bleed |
| Elder thornback | 5 | Boss, dismemberment |
Spiders have a stun multiplier that determines how easily they are staggered. Cave ticks stagger easily (0.2); Thornbacks are hard to stagger (0.02); the Elder Thornback is almost immune (0.0005). That number is why you cannot stun-lock a boss.
Humanoids
Survivors are traders first and enemies second. A friendly survivor will not fight back; an aggressive one can be killed. A survivor dies below 200 HP, and each of their items has a 66% chance to drop.
Killing a trader is a bad trade in every sense: -10 Mood, +30 Trauma, +30 Sickness, and only +60 Resilience XP. The loot is not worth the medical bill.
Plants
Tentacle-plants and Grabber-shrooms are fixed hazards. They do not chase, do not drop loot, and punish players who sprint through vegetation. Cut them from range or walk around.
Layer-by-layer threats
Layer 1: Gravel Lands
Shade crawlers and three traps: geysers, jump pads and spike traps. The spike trap is the real killer — it hits hard, it is hard to see, and it can end a run before you have bandages.
Layer 2: Deeper Gravel Lands
Shade crawlers and cave ticks, plus barbed fences, bear traps and cave-tick spawners. The layer is dark and flooded. Most deaths here are infection from a tick bite, not the bite itself.
Layer 3: Dried Desert
Sand stalkers ambush from sand; shade crawlers patrol. The trap list is the longest in the demo: turrets, stalactites, landmines, waste pipes, bear traps and barbed fences. Oil pools are a drowning hazard, not an enemy, but they kill as reliably.
Layer 4: Wasteland
No enemies at all. The danger is environmental: radiation, sound cannons, coils, spent fuel, landmines, turrets and stalactites. This is the layer where players relax and die.
Layer 5: Overgrown Depths
The full roster: shade crawlers, sand stalkers, cave ticks, overgrown ticks, tentacle-plants, thornbacks and the Elder Thornback. The layer is also the best-fed in the game, which is the trade: food is abundant, and so is everything that eats you.
The Elder Thornback
The Elder Thornback is the demo's boss. Three spawn when you enter Overgrown Depths. It is slower than you, and it is still the most dangerous thing in the game.
The sense of impending doom
Within 101.25 tiles, you get the "sense of impending doom" moodle. It:
- Wakes you immediately and sets energy to 10.
- Spikes adrenaline to 100.
- Darkens the edges of your vision.
- Temporarily reduces mood by 25%, including negative mood.
The moodle is a warning, not a debuff to fight through. When it appears, you are already in its territory.
The dismember attack
A hit from the Elder Thornback:
- -4 Mood.
- Rolls a random limb for dismemberment, excluding the head, chest and abdomen.
- On the affected limb: -100 skin, -50 muscle, +1.5 L/m bleeding, +100 pain, +30 trauma.
- If you are already disfigured, the hit kills you outright. Otherwise it disfigures you or gouges an eye.
The adjacent-limb damage is the part players miss. Even a "successful" hit that does not remove the limb can leave the neighbouring limb at zero muscle.
How to survive
- Run. It is slower than you. Do not try to trade hits.
- Slide down Sandvines. Chasms with Sandvines are the fastest escape route.
- Break line of sight. The doom moodle persists while it is chasing; distance is the only reset.
- Do not fight it in water. Swimming is slower than running.
- If you must fight, use the heaviest single-hit weapon and dynamite. Staggering it is nearly impossible: even 100 damage stuns it for about 0.05 seconds.
The best weapons guide covers which weapons actually damage it.
Trap list
Traps kill more players than enemies in the early layers. The full demo list:
- Geyser
- Jump pad
- Spike trap
- Barbed fence
- Bear trap
- Cave tick spawner
- Turret
- Stalactite
- Landmine
- Waste pipe
- Sound cannon
- Coil
- Spent fuel
- Skullcrusher
- Banana-plant
- Gunmine (layer 6, unreleased)
Disarm spike traps by throwing something at them. The thrown item is destroyed or drained, so use junk. Bear traps can be triggered and reset; turrets can be avoided by breaking line of sight. Landmines are visible if you look; sprinting is how you find them.
Combat basics
- Hit and retreat. Most enemies have an attack cooldown; use it.
- Commit to a hit and back off. Enemies have short attack cooldowns; the window after their swing is your turn.
- Do not fight with a fractured arm. Your swing speed and damage collapse.
- Fight with your back to a wall. The ragdoll physics can throw you into a pit.
- Carry a bandage, not a second weapon. The bleed after a fight is the real cost.
Drops
Spiders drop a variety of crafting materials. Humanoids drop each item from their trader inventory at a 66.6% chance. Plants drop nothing. The Elder Thornback drops valuable loot — enough to justify the fight if you can win it without losing a limb.
The Wasteland is environmental only. Players relax there and walk into a landmine. Keep the same discipline.
FAQ
What is the strongest enemy? The Elder Thornback. It can remove a limb in one hit.
Are there enemies in layer 4? No. The Wasteland is environmental only.
Can I avoid the boss? Yes. It is slower than you, and you can run to the exit.
Do traders attack? Only if hostile. Friendly traders do not fight back.
What is the best weapon against spiders? A fast machete or a rifle. Stagger matters more than raw damage against ticks.
Do enemies respawn? Spiders spawn from spawners and layer generation; the boss spawns on entry.
Sources and further reading
Related guides
More Casualties: Unknown Guides
Every weapon in the Casualties: Unknown demo ranked: damage, swing speed, durability, ammo and which weapon fits which layer.
How blood volume, bleeding rate, tourniquets and transfusions work in Casualties: Unknown, and the order to treat a bleeding limb.
The three playable characters in Casualties: Unknown, what Experiment can do in the demo, and what is actually confirmed about Milky and Dune.
How crafting works in Casualties: Unknown: the five tabs, Intelligence requirements, failure tiers, blueprints and the recipes worth making first.
What the free Casualties: Unknown demo includes, how long it takes, where it ends, what carries over and how to install it on Steam.
All six Casualties: Unknown presets plus the 41 custom run settings, with defaults, ranges and the options that actually change survival.
Casualties: Unknown endings explained: the confirmed story goal, the unreleased final layers, what the demo does at layer 5, and what is still speculation.
A practical triage guide for Casualties: Unknown: bleeding, infection, fractures, pain shock, fibrillation and the items that treat each condition.