On a timeless placeless moment, when the Big Bang created this Universe,1) with all particles conforming to its universal constants. It also created another collection of Hypothetical Subatomic Particles which was sentient, Improbably so. It also had the ability to tweak the universal constants for itself.
As the Universe kept expanding it observed many other sentiences, some interesting, some boring. Among these it found the humans to be the most improbable2) and unpredictable,3).
After the EMP wars, it noticed a place which was teeming with Improbability and found Horatio, they immediately developed a liking for each other and the sentience took up residence there4). It arrived as a male human but Horatio immediately suggested a form that much suited its taste.
He's a lanky and scruffy Kittymorph,5) 5'11" with Black shaggy fur6) and an extra long tail. Wears dark and smoky oval glasses7), his eyes are equally black, unless he's playing with improbability, when they glow a pupil-less red. After he left the island, all that was left was his body in a robotic form. The same in shape but made of shiny black metal.
Once, Petra was seen dragging him from the Kissing Booth to her parlour and hence he sports red fur tattoos on his shoulders and arms.
His appearance does not seem to change much whatever his race be, midgethood just chops off a few inches from his height, while mutation just turns his tail scaly. Even as a Joker, he only wears his hat.8)
Sitting on high places.
Rigging up stuff with explosives.
Rigging up gremlins with explosives, and exploding them.
Cleaning his glasses.
Butting in with profound and utterly useless comments.
Hardly making any sense.
Irritating his friends. 9)10)
Basically being unsocial, he hardly had friends when he arrived first. Later on he found that interacting with other sentiences to be quite amusing and gained a number of acquaintances11), he also gives a lot of leeway to his male biology. and thus has a marked preference for females. His general quirkiness and his social ignorance have earned him a membership in clan QQQ.
He generally moves at light-speed, but does not violate relativity12) due to tweaked Universal Constants13). Though at that speed he's more waves than particles, so the air ionizes and his movement tends to leave an ion-trail which takes some time to dissipate. He also can generate various sorts of improbabilities by changing Universal Constants but for some unknown reason he hardly does that.
He does not sleep, but meditates when he has nothing to do. The need to meditate and his love of high places lead him to grow fond of the tallest trees and suchlike in each outpost which he adopted as his home. Repeated sabotage attempts14) and his love for explosives15) lead to the rigging up of those structures with explosive traps16), which currently include the tallest trees in the Common Ground17), Kittania, Pleasantville, Squat Hole, New Pittsburgh and AceHigh; a wooden pole in NewHome18) and a metal post in Cyber City 404.
He's good at making stuff, and gets things done quickly 19) He created the CG Tree AI for selfish reasons but opened the music controls to all. He's generally helpful, but has a massive ego that spills over into the 13th dimension, so he prefers being asked first. He's quirky and unpredictable, but always polite.20)
NesQuarX had been seen less on the Island21), and unfortunately had not met eVe for more than a month's Island time. It was not an amusing experience for him. That was alleviated though. He had married her.
But sadly, his travels were a bit too much for Genevieve to handle,22) when he realized what a terrible amount of pain this was causing her. He left the island, had Horatio turn his body into an indestructible metal statue at the foot of the AI tree. 23)
Update: The statue has vanished.24)
Another update: Not yet known when or how, he seems to be back on his treetop, cleaning his glasses...