i dont remember my first warriors oc exactly.. i DO however, remember a few names from VERY old characters, as well as semibackstories. all four of them are from animaljam c': i no longer use them but i still remember them so :L
Dawnpelt was a brown Thunderclan shecat. She was also the leader, Morningstar's adopted daughter. I think I was using her when our clan was attacked by FIVE SCOURGES (some where female too... all powerplayers), and I also used her during the Great Fire. (animaljam was crazy yo)
Honeywhisker was ALSO a brown Thunderclan shecat, but she had light and dark patches. All I remember about her was that she had an apprentice, and I got into an argument with someone because they also had the name Honeywhisker. I asked my apprentice to prove to them that I didn't steal their name... and.. my apprentice didn't know my name. Haha. #goodtimes.
Ok I remember wlmost nothing about this character but she was a thunderclan medicine cat named Silverleaf or Silvermoon??? I think it was silvermoon? But she was grey with a white underbelly and she had green crescent markings on her because #animaljam. I don't remember her backstory at all, if she even had one, but I remember her looks and name.
Lastly is Appledawn. She was a dark brown (i think? but definitely brown) shecat, and had an apprentice named Foxpaw (later Foxcloud). Appledawn and Foxpaw were the last surviving members of Skyclan in that roleplay, but all I remember about it was someone freaking out and asking what happened to Skyclan (which i was going with the original book idea before Firestar broguht them back), and Foxpaw's warrior ceremony. I went the 'by the power invested in me by me' route with it before redoing it correctly. I also remember trying to help Foxpaw find a name he liked. I suggested Foxpelt (whoahh!! but him and yewclan have nothing to do with each other), and he freaked out because he thought pelt meant poop

Currently, my oldest warriors oc that i still hse is probably... Aspenoath. She has a long and complicated backstory which I spent a long time on, but I love her and her family.