listen the only thing i find rong with this whole herobrine story is (he visits you in single player), for the past couple weeks i have been going through the class files, mod skins, and i found nothing leading to the mob for herobrine.
BUT, what i did find is a class file for an unused mob i cant access the inner coding because i dont have the software but "it must be there for something..."

I heard some suspicious rumors, but I almost know for sure thet just recently, Notch declaired that Herobrine never existed in the first place. However, this could be one of Notches pranks, like the April Fools "Steve and co Supply Crate". I also heard Notch did a tad bit of work on Minecraft. I don't really know about this because Herobrine has always been reported, and it certainly could be real. The wiki post is also interesting.

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I just read your other post, of which I believe is almost definitely a fraud. I say this because A. you and your friend have very similar names, and B. I have gone through the .lang file of Minecraft (the place where all almost all the text is stored) and found nothing like this. The closest thing was the generic file. That just said <Name> died. Also, nobody going through the more deeply coded files haven't seen anything like that.

In your favor, Notch has "removed Herobrine" a suspicious number of times. Just read the update logs.

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I looked on the forums and saw no Herobrine storys whatsoever. This goes along great with the story on the wiki about a moderator deleting all Herobrine stories. Wow! This comment is getting long!

Quotes (from wiki):
[size=200%]"[/size]The Herobrine stuff is awesome and kind of scary at the same time. It really shows how little control a content producer has over the content.

I've publicly told people there's never been any such thing as Herobrine, and that I don't have any dead brothers, and that letting too many animals die in lava is a fool proof way to summon him but that you don't need to be afraid of him. He only means well, he's looking out for you, trying to warn you of the dangers you can't see. There certainly are NO physical manifestations of Herobrine that will sneak out of your computer if you leave Minecraft running at night, looming over you as you sleep with his pale eyes inches away from your face, as he tries to shout at you to wake up. Sometimes you wake up with a jolt, and he's gone, and all that lingers is the memory and faint echo of his wordless screaming. Of course it was just a dream. There's no way a morally dubious ghost with a god complex could at any point decide to haunt the children who play my game "for their own good", as there is NO SUCH THING. etc etc[size=200%]" -Notch
[/size]

No