The codo /ˈcəʊdəʊ/ is a tan and rust-colored stranger with a robust build and large head. Its thick skin feels like a sweaty human palm. Otherwise, its exact appearance and behaviour differs between hemispheres.

Regardless of which hemisphere it occupies, when "hurt", the codo does not bleed. It heals from lacerations readily and without scarring, but cannot regrow excised flesh, such as a sliced-off leg. Should it sustain a loss of more than 19% of its overall physical mass, its every tissue becomes hard and plaster-like before breaking apart to powders-and-pebbles.

A youthful huskiness is characteristic to all codo when speaking, though the pitch varies between individuals. Its projection is always resonant, and its tone, confident.

Though not being perceived as overly loud in volume, the codo's voice can be felt in the body of all listeners.

In its disposition, the codo is stalwart, yet aloof. Though tirelessly protective of the tower which it guards (maintaining a distance of no more than thirty-three feet, it does not enter inside.

Pairs of codo pass the time by engaging in wrestling-like displays of strength. Each codo attempts to pin the other, utilizing grapples, flips, and submission holds. Though energetic and boisterous, these displays do not result in injury to the competitors. A pinfall of more than ten seconds determines the winner and loser, after which both individuals disengage.

In general, the older of the two tends to be the winner, with younger individuals being more brash and careless in their motions. Fights average between one and sixteen minutes in length.

The codo's presence changes the appearance of the tower which it guards, a phenomenon observable only from a distance. This holographic illusion starts from the base of the tower and works its way up in a process than takes anywhere from ten to one hundred years.

The codo watches any approaching sensitive with a gallant diligence.

Should the sensitive enter the codo's territory, the stranger turns animalistic in its aggression. It rushes towards the sensitive, using its sharp claws and teeth to sever limbs or tear off chunks of flesh. Losing all language or social decorum, it becomes so vicious that it will even injure its companions in the chaos.

Though the group seems to "feed" off of the sensitive, severed limbs or chunks of flesh are never swallowed, but are instead chewed up and spat back out onto the victim's body.

Once the sensitive is dead, the codo grows more listless with each bite, until its interest fully wanes and it abandons the mangled body altogether, as well as its aggressive behaviours.

The oldest codo in the group pushes the corpse from the territory's perimeter.

The codo allows a sensitive through their perimeter if and only if the sensitive says the password (unique to each tower) while within ten feet of their territory's edge. Following this, the codo grows indifferent to the sensitive's further actions, even tolerating injury.

When pulled from its territory, the codo experiences a massive loss of stability.

It dies within minutes, leaving behind a crumbling and disfigured plaster corpse.

As the codo ages, its wrestling grows more violent. It bites or yanks the flesh, uses less safe grapples, or dislocates its opponent's limbs. Before long, the aging stranger loses its sportsmanship altogether.

As it ages and grows vicious, however, so too does it grow weak. These attacks rarely cause serious injury to its former companions, which do not tolerate the aggressor, pushing them from the territory, forcing their degeneration to plaster.

The final codo in a group slumps over without fanfare, its corpse becoming fetid within the day, then statue-like within the week. Its decayed flesh becomes as hard as granite, the monument standing as a grotesque icon for years to come.

The death of the codo does not affect the appearance of the tower, which remains obfuscated.