- Backrooms: Code Yellow entity list organizes every creature by M.E.G. number, name, and habitat.
- Habitat ratings range from Rare and Uncommon to Common, Majority, and The Backrooms-wide.
- High-threat picks: Smilers, Hounds, Skin-Stealers, and Wretches appear on a Majority of levels.
- Survival rule: Match your route to entity density — dark, humid, and aquatic levels are hotspots.
- Check frequently: Many high-numbered entries remain {NO DATA} and get updated over time.
Understanding the Backrooms: Code Yellow Entity List
The Backrooms: Code Yellow entity list follows the classification system maintained by the M.E.G. (Major Explorer Group), the same framework documented in the Backrooms Entity Database. Every non-level-based entity receives a number, a name, and a habitat rating that tells you how often you will cross paths with it.
The habitat tag is your single best planning tool. An entity rated Majority appears on over 50% of levels, while a Rare entity shows up on fewer than five. Route your expeditions around the densest habitats first.
Core Habitat Categories
| Habitat | Meaning | Threat Planning |
|---|---|---|
| The Backrooms | Found on all levels | Always prepare for it |
| Majority | Over 50% of levels | Standard loadout assumption |
| Common | More than 20 levels | Frequent encounters |
| Uncommon | Roughly a dozen levels | Situational prep |
| Rare | Fewer than 5 levels | Specialty route only |
| Level (#) | Locked to one main level | Level-specific strategy |
| Extinct / Nearly Extinct | Wiped out or nearly gone | Lore interest only |
| Obfuscated | Location deliberately hidden | Community research target |
Notable Status Flags
| Status | Example Entities | Notes |
|---|---|---|
| Extinct | Homo Callidus (Entity 70) | No live encounters |
| Presumed Extinct | Forevermore (Entity 104) | Unconfirmed sightings |
| Nearly Extinct | The Unfinished Symphony (Entity 110) | Most reports at Level 2 |
| Unknown | The Cameraman (Entity 1) | Habitat concealed |
| {NO DATA} | Entities 68, 91, 106+ blocks | Awaiting documentation |
Tier 1 Dangers: Entities 1-20
The lowest-numbered entities are the classics — the ones you will meet constantly and must recognize on sight. These entries dominate the Backrooms: Code Yellow entity list threat tables because their habitats cover most of the map.
| Number | Entity | Habitat | Danger Notes |
|---|---|---|---|
| 3 | Smilers | Any level with darkness | Avoid dark corridors entirely |
| 8 | Hounds | Majority | Fast pursuit, aggressive |
| 9 | Facelings | Majority | Behavior varies by instance |
| 10 | Skin-Stealers | Many, notably Levels 1-3 | Mimics wanderers — trust no one |
| 15 | Wretches | Majority | Hostile in most documented cases |
| 16 | Bone Thieves | Majority, indoor levels | Sneaky, indoor-focused |
| 5 | Clumps | Many, most notably Level 2 | High density in tight spaces |
| 2 | Windows | Common, notably Level 188 | Observation hazard |
Darkness Trio
- Smilers lurk in any dark level
- Lighters favor dim levels too
- Carry light sources at all times
Mimic Threats
- Skin-Stealers copy wanderers
- Facelings look almost human
- Verify identity before trusting
Pursuit Threats
- Hounds run down targets
- Wretches swarm in groups
- Plan escape routes in advance
If a "wanderer" appears in Levels 1-3 without gear or supplies, treat them as a possible Skin-Stealer. Back away, keep visual contact, and never follow them into enclosed rooms.
Habitat Hotspots: Where Entities Cluster
Certain environmental conditions concentrate entity activity. Cross-referencing these hotspots against the Backrooms: Code Yellow entity list lets you predict encounters before you enter a level.
| Environment | Common Entities | Prep Priority |
|---|---|---|
| Dark / lightless levels | Smilers, Lighters, Peekers, Needlelimbs | ★★★★★ |
| Aquatic / humid levels | Pool Guards, Cells, Sticky-Centipede, Vixites | ★★★★ |
| Vegetated levels | Blood Wasps, Devil's Ambrosia, Aurelia Suffocans | ★★★★ |
| Industrial levels | Silver Slimes, Goalbots | ★★★ |
| Shopping / retail levels | Mannequins, Slugreads | ★★★ |
| 1900s-style levels | Radio Demons | ★★ |
| Winter-type levels | Mushroom Maw | ★★ |
Entity 14 (Rainbows) explicitly excludes levels classified as the Main Nine, appearing instead on Level 10, Level 199, and other suitable outdoor environments. Use this exclusion when charting rainbow-safe routes.
Steps to Map Entity Density in a New Level
Check the level classification
Identify the level number and environment type — dark, aquatic, industrial, or outdoor — before entry.
Cross-reference the entity list
Filter entities whose habitat includes that level or environment type, prioritizing Majority-rated threats.
Mark Level-locked entities
Note exclusives like Konelo (Level 108), Lights (Level 9.7), and Ravager Apes (Level 990) so you know what to expect nowhere else.
Plan around hotspots
Adjust your route to avoid the densest cluster zones — tight corridors for Clumps, stagnant water for Hydrolitis Plague.
Survival Rankings: Mid and High-Number Entities
Beyond Entity 20, the list diversifies into environmental hazards, phenomena-class threats, and rare specialists. These are the entries most players overlook — and pay for it.
| Number | Entity | Habitat | Risk Level |
|---|---|---|---|
| 11 | Hydrolitis Plague | Stagnant water | High — never drink untreated |
| 30 | Peekers | Level 9.6, pitch-black areas | High in darkness |
| 41 | Pool Guards | Aquatic levels | High near water |
| 61 | The Rot Infection | Most levels with humans | High — contagion risk |
| 63 | Predatory Doors | Uncommon, entity-dense levels | Medium — door discipline |
| 67 | Partygoers | Majority | High — avoid "parties" |
| 88 | The Reality Magnet | Rare, metal-rich levels | Medium |
| 145 | Tear Mold | Widespread (lore-linked) | Medium |
| 193 | Cindy | Obfuscated | Unknown — avoid engagement |
Entity 61 spreads through most levels with human presence. Quarantine any contact with infected wanderers, and never share supplies or water sources with unknown survivors.
Some entities actually help route planning. Mercies (Entity 26) and Warding Phantasms (Entity 75) are associated with levels where dangers are present — their presence signals you should be extra cautious, giving you an early warning system.
Entity Survival Checklist
Pre-Expedition Entity Prep:
- Memorize the top 10 Majority-habitat entities
- Pack light sources for Smiler-infested darkness
- Identify water sources safe from Hydrolitis Plague
- Learn Skin-Stealer identification cues before Level 1-3 runs
- Note all Level-locked exclusives on your route
Tracking {NO DATA} Entries and Updates
A striking feature of the Backrooms: Code Yellow entity list is how many numbered slots remain undocumented: Entity 68, 91, and the large blocks from 106 through 199 are marked {NO DATA}. These gaps are active research frontiers.
| Data Gap Range | Count | Implication |
|---|---|---|
| Entities 68, 91 | 2 slots | Isolated unknowns |
| 106-199 blocks | 70+ slots | Largest frontier |
| 200+ (CE sections) | All | Reserved classifications |
Treat {NO DATA} slots as unsurveyed territory, not empty territory. The Backrooms Entity Database updates continuously, so re-check habitats before major expeditions — a Rare rating can shift to Uncommon as sightings accumulate.
Entity List FAQ
Q: What is the Backrooms: Code Yellow entity list based on?
It follows the M.E.G. classification system: every non-level-based entity receives a number, a name, and a habitat rating describing how frequently you will encounter it across levels.
Q: Which entities should I worry about most?
Majority-habitat threats like Hounds, Wretches, Facelings, Skin-Stealers, and Smilers appear on over 50% of levels (or any dark level, for Smilers). Learn these first.
Q: What does {NO DATA} mean in the entity list?
It means the numbered slot has been reserved but not yet documented. Do not assume the level is safe — treat these entries as unsurveyed rather than empty.
Q: Are any entities in the Backrooms: Code Yellow entity list extinct?
Yes. Homo Callidus (Entity 70) is listed as Extinct, Forevermore (Entity 104) as Presumed Extinct, and The Unfinished Symphony (Entity 110) as Nearly Extinct, with most reports at Level 2.