I have plenty of OC's, some more developed than others, but this post would be a mile long if I listed them all. As such I'll only share my favorite OC's, and their profiles will be summarized.
Snowraven - a ShadowClan cat (in an alternate universe) who had a fairly normal upbringing and is a genuinely likeable, dependable figure, even if he is a bit of a recluse. After accidentally killing an elderly rogue when he was apprentice and feeling guilty afterwards, he took the time to pick apart the warrior code line by line, eventually reasoning that not only did outsiders not matter, but he began calling them "false cats", declaring that they could never feel any semblance of compassion, love, loyalty, honor, or any kind of morality, and often comparing them to rats. Instead of chasing away outsiders, he merely killed them with no second thought, like if a cat were hunting a piece of prey. He felt no hatred, jealousy, or bloodlust - he was just "doing his job". After exterminating a queen and her six young kits on the edge of ShadowClan territory however his actions came under much further scrutiny from within his own Clan, but the acting leader at the time, Gorsestar, while disagreeing with his assessment regarding the value (or lack thereof) of outsiders, never truly punished Snowraven for his actions - he only scolded him from time to time. Eventually Snowraven became deputy and then leader, and during his time of leading ShadowClan at one point he ordered mass raids to sweep across the nearby Twolegplace to kill as many loners, kittypets, and rogues as possible, and their bodies were said to have been piled higher than the greatest of boulders. When he and his deputy were eventually overthrown and killed, it's unknown if he went to StarClan or the Dark Forest, but probably the latter.
Petalfall (**alternate version) - A PineClan she-cat who lived a very tragic life. From when she was born she was ignored entirely by her father, who was too consumed by his duties to even acknowledge her as his own daughter, and after her littermate, Honeykit, died from greencough (she was always the more favored kit out of the two), her mother neglected her even more so than before, denying her access to her milk even though she was only a couple moons old. When Petalkit reached 6 moons of age it took almost an entire moon further for her to be named as a warrior, as the entire Clan - even her leader - continually forgot about her existence. Her mentor, Sandstone, started pawing after a rogue and rarely trained his apprentice as a result. PineClan's current leader, Jaystar, did nothing outside of scolding the warrior a couple of times, and as such Petalpaw was forced to train herself. It took Petalpaw 18 moons before she was eventually named a warrior, even though her training wasn't nearly complete. Later on in her life she discovered that her entire life had been a lie. Her mother or father didn't lay in PineClan, but elsewhere, somewhere in Twolegplace in the form of a rogue. For a while she believed her leader's words, that her mother had been a rogue that had been found dead, and Petalfall and her sister had been taken in as kits to be raised as PineClan warriors. The truth that eventually leaked out was far more disturbing however - as it had turned out, her mother had not only been murdered by a raiding party, but so had the mothers and fathers of numerous kits within PineClan's ranks. In short, their parents were killed and the kits were dragged back to the Clan and trained to be fighters. Petalfall seriously considered leaving for some time but was tragically killed by a fox one early morning after she had decided to hunt alone, a total meaningless death. Worse still, just as she had been forgotten in life, she barely remained among the ranks of the Risen (their version of StarClan) for more than a few moons before fading away entirely, the final remnants of the memories of her disappearing from the world.
(**I have an alternate character bio of Petalfall that is completely different, so this remains her second bio for now. I might separate them and rename this version of Petalfall sometime later.)
Moon - She was found in a Twoleg basket floating downstream by a rogue queen by the name of Jade. The she-cat took Moon in as her own and nursed her alongside her biological daughter, Briar. Three moons later a flashflood hit the area, trapping the cats in the abandoned Twoleg nest in the meadow beside the river that they had long since called home. Briar was swept away by the current and quickly drowned. Days later Jade escaped with Moon to a higher elevation and she continued to care for her for moons to come, still allowing her to nurse, and this habit would continue for several moons after due to a lack of prey and Jade coddling Moon a little too much. At the age of 5 moons Jade gave the full story to Moon of how she had found her as an orphan, and a moon later Moon began training herself in the ways of hunting and fighting to prepare herself for her eventual journey. Jade knew she wouldn't stick around forever - her curiosity and determination burned inside her brighter than any flame. At the age of 9 moons Moon said goodbye to her, promising that they would meet again one day, and set out on her mission to find her mother (and if she could, her father as well). I'm currently doing a roleplay with someone where she is travelling with another she-cat named Feather, and the two might enter a romantic relationship at some point (although the RP will have and does have a lot, lot more to it than that), so for now, at the age of 22 moons, her future is unclear. Briar is still alive though, and is gently guiding her non-legitimate sister in spirit form.
Flowerpaw - a former kittypet who joined ShatteredClan at the age of 6 moons to become a Clan cat. Her mentor, Snowcloud, an equally important character in this story, detested outsiders to the absolute limit. His leader at the time, Hollystar, who was far more progressive thinking, gave Flowerpaw to him as his apprentice as a "learning exercise", a way for him to get to know her and hopefully develop some sort of tolerance towards non-Clanborne cats. Tragically he murdered his apprentice not one moon later, having pushed her off the side of a cliff, and as a result he was exiled after an investigation proved him to have been the killer. He would later rejoin ShatteredClan after Hollystar had fallen ill and lost her final life.
Hollowfall - a PineClan tom who never felt at home in Clanlife. Soon after earning his warrior name, Hollowfall, he left his Clan to life his life as a loner (or a "wanderer", as he called it), and would spend his life travelling the world to see all of its wonders, meanwhile meeting many, many cats along the way.
Crescentfall - A middle-aged SkyClan tom who was born into a time of great turmoil when his Clan was under various threats, including a serious leafbare that had killed off half of his Clan while he was still an apprentice, and now challenges from the other Clans and a highly organized band of rogues from within Twolegplace. He was forced to mature quickly and spent much of his free time gathering as much information as he could on how to help support a Clan and what mistakes previous leaders, deputies, or other notable figures had made within recent memory. He was always bested by his brother, Ashcloud, who was always deemed wise than he was. A great jealousy developed inside of Crescentfall that would surface later in life.
Crescentfall is often characterized with possessing a deep and incredibly powerful voice and an outstandingly skilled as a master wordsmith to match. Such a skill is uncommon and grossly undervalued by the Clans, but through his apprenticeship he developed impressive fighting skills as well.
As he aged he began to accumulate more and more knowledge on Clan history, and was particularly fascinated in the Dark Forest, which would eventually lead to dangerous levels. He reasoned that such a power could never truly be destroyed, if it existed at all, and that it would one day return. Eventually he would be contacted by these same long dead cats and while he thought he had won the battle of the words early on, the representatives of The Place Of No Stars had over time succeeded in poisoning his mind.
Crescentfall's downwards spiral into darkness began with him murdering his brother, Ashcloud, after he had been named as deputy. He was excellent in covering up his tracks, and eventually, perhaps inevitably, he became his successor. He served for many moons before his leader, Blossomstar, lost her last life to a fox attack. There Crescentfall took over, establishing himself as the sole voice of power within SkyClan, although he had a few particularly loyal subjects that somewhat acted as his deputies. From then on he began changing SkyClan, shifting it to his purposes, training cats to learn new battle moves while creating alliances with rogues from Twolegplace, and he was quite pleased with his creation, the dawn of a new era, but in reality his ideas came from nowhere else the Dark Forest, and in many ways SkyClan would then be considered a pathetic attempt at replicating the Dark Forest. Crescentfall's soul became dark not out of greed or for the sake of being evil, he merely wanted his Clan to survive and to become as dominant as it had been many moons ago. In a way he succeeded. The threats from the other Clans and the rogues subsided and SkyClan became feared and respected once again. While he was eventually overthrown and killed, and had caused the deaths of hundreds of cats during his campaign, in a twisted way, if it were not for him, SkyClan may not have survived.
(I hope this wasn't too much, I got a little bit carried away.
Also apologies about a lot their lives being bleak, I like adding drama to my characters or their stories.)
Edit reason: spelling errors