All of my main oc’s I have had for a super long time! While Alice, Nico, and Mary would be older than Alex they look quite different from before. Alex on the other hand look’s basically the same since I originally made him. Also I made the four of them very close together time wise so I think he still counts, I believe I was 11 when I made him (and the other 3). I’ve had him for so long and he is still one of favorite characters!
Or the oldest OC that you have.
I’ll start with a classic - Spike. I’ve had him since I was four. Most of his art is digital & requires uploading to his page. (Just a word of warning lol once you look at his profile you’ll be slapped with lots of old art)