partygore

Sentinels are pseudo-mammals (Think pangolins and armadillos if you want a specific animal comparison on appearance, they're not reptiles even with their scales!) made up of frankenstein'd parts of dead wanderers and entities. In my personal headcanon (Shared with oomfie Hollow/partygore), the Backrooms/Superstructure itself is a simultaneously living and non-living construct, beyond human recognition. It has the ability to take old, dead flesh and absorb it into itself, repurposing it in the creation of specific entities. All entities were originally created this way, however a majority of said individuals have long since died (Present-day's entities were created via reproduction, whether it be asexual or otherwise, varies from entity to entity.)

This is, of course, with the exception* of Sentinels; though no new Sentinels have been recorded being 'born' (Theorized the 'limit' has been reached.). They noclip into the world covered in blood and viscera, scaleless skin mottled in appearance. Very prone to disease and death at this stage, it's crucial they're immediately taken to a space where they can rest and be protected. Many cannot walk properly in this stage and must be taught that too. They're capable of holding their own within a couple of months to a year.

All Sentinels are 'born' on Level 52 (Two variants exist. Polar, born to 52B, and standard, born to 52A.) and were created with the sole purpose of guarding and caring for the other entity they cohab with; Partypoopers. Some choose to be guards, others medics, some glorified babysitters for the children whose parents are busy scavenging or partaking in other duties (Sentinel caretakers will have a certain number of Partypooper 'pups' in their possession at a time. This can swap around quite often, groups trading depending on various factors. A great majority of Partypoopers aren't the best parents, but this is required for their survival considering where they live, even on a safe, stocked level like 52.).

Sentinels must constantly be working, or they'll physically and mentally deteriorate. They can live for over 250 years, but many die early due to understimulation, and several have died during the war. The 'Fun War' caused them to scatter, and they no longer have a designated native level (Only Odinn remains, withering away on her once shining throne, refusing to let go of the past.).

Sentinels partner with one another (Or other entities) for life and will remain loyal even after death, refusing to partner again. If one is feeling extreme emotions or dying, their colors begin to fade. Sentinels can be revived using large amounts of blood, but the corpse must be immediately transferred to a cold space to not be disturbed. Sentinels do not begin decomposing for decades unless tampered with. Despite this, it is incredibly disrespectful and frowned upon to revive a Sentinel who died of grief or natural causes. Resuscitation is rare, needing proper bloodwork and a large number of willing participants, only a handful of successful revivals are recorded.

PHYSICAL CHARACERISTICS OF ALL SENTINELS:

At least 2 heads, rooted directly into their brain. Can have up to 6 heads. Lenses with any shaped/colored pupil sit within these heads. Sentinel brains are stored in a sturdy neck stump, near impossible to break. Heads are fragile in comparison, defended profusely during a fight. If a head is pulled at or crushed, Sentinels can suffer mild to extreme brain damage.

Thick, near-impenetrable scales covering their backs, smaller ones across their bodies. (Polar Sentinels have large spines/studs jutting out just beneath their tails). All scales are made up of organic metals. Sentinel scales can shed and be gifted. It's considered a very intimate gesture to gift scales, reserved for partners, family and closest friends. Aforementioned scales have the ability to be forged into strong armor and weaponry, making them a valuable but rarely seen find.

Fur on their underbellies, around their neck stumps and on their wrists (Only with Polar variants.). Fur sheds when stressed and can disappear for years.

Shoulder and hip spines (More noticeable on Polar variants.).

Specialized breathing vents lining their sides.

Varying in height from 7-10' tall (Standard) and 11-16' tall (Polar). Taller and shorter can exist, with the tallest recorded Sentinel referring to herself as 'Vega' at 18' tall.

1-3 pairs of arms.

Large, strong claws for digging.

Any muscular or chubby body type. A skinny Sentinel is a sickly/understimulated Sentinel.

Sentinels lack biological sex and reproductive organs. Their digestive systems are notably also incomplete, ending at the small intestine, which breaks down any food/liquid not disintegrated by their strong stomach acids and converted immediately into energy.

The ability to switch between a quadrupedal and bipedal position.

A mouth located just beneath their chests, lined with sharp, conical teeth. Seamlessly closes, not visible unless a Sentinel is threatened or eating.

Natural markings of any sort. If a Sentinel is born with low-visibility or no markings, they'll paint them on themself.

Warm-toned skin (Standard variant) or cool-toned skin (Polar variant). Do not stray far from grey and darker tones (Unless leucistic or albino.) and are never bright, saturated colorations.

Rarely, mutations can come about, also called 'gifts'. They come in two forms; Maelstrom and Firebane.

Firebanes have a special flammable coating on their scales and teeth. They can self-combust and breathe fire with the clicking of their teeth/scales (Odinn is a firebane.). They're an extreme version of the unmutated Sentinel, which can only heat their scales to extreme levels. All members of the species radiate an ambient heat, comforting when not enraged or afraid.

Maelstroms have a velvety layer of fur on their scales, microscopic thin. They conduct extreme static electricity by rubbing their scales together.

FULL LIST OF 'CANON' SENTINELS:

Odinn RIOT Sleepwalk Aperture Vega Wisteria Amp Tiger Lily Shiv Atlas Jasper

*Many humans still become entities this way, however true constructs no longer exist aside from Sentinels.

If I end up remembering something else about them, I'll reblog and add onto this, I hope reading my ramblings is entertaining, I adore these fellas and they're the result of almost three years of worldbuilding and roleplay! I do not allow the creation of Sentinels for anyone else other than close friends for personal reasons, I ask anyone reading this do not create one of their own as a boundary. You can take inspiration though, I don't own the idea of anthro camera head monsters!