Hello there
No, that was not me. The actual creator's origin is unknown, to be honest.
The originator of the Herobrine legend made this graphic:
minecraft.gamepedia.com/media/…Find that guy, and you find the creator of Herobrine. But so much time has passed since that image was made (at least 8 years, by now), that it would be a miracle if you could find them. All we were able to collate is on the Herobrine page, on the Minecraft Wiki. The author of that image has been lost to time, and has not stepped forward.
My role, was an admin of the wiki. I wanted a Herobrine page, the others disagreed. We squabbled, I got demoted a few times, but then, I got that page up and past the head mods, as a promise it would curb "Herospam"(the act of spamming Herobrine into other pages for fun). This promise worked out, and the spam fell to nearly zero, once we gave it it's own page.
That is the full extent of my involvement with Herobrine. I recall the original streams vaguely, but I don't know much more besides the geographical setups of the rooms that Herobrine was found in, and that he was, by all accounts, a retextured door/painting.
If there is anything else you would like to know, please ask away! If not, I hope what I've said is even remotely helpful.