Many people think signs appearing are from Herobrine. Those are glitching or someone trolling you. Some people say Herobrine is said like Hero Brin. Like my friend. Others say it is Hero Brine.
Herobrine is not in Minecraft. He is just a rumor for Minecraft. He appears in others games. It is impossible to see him in Minecraft. Herobrine is said to look like Steve on Minecraft and have white eyes. He appears like that on the game Brocraft. These were my facts.

Okay, but if you plan on getting badges don't spam posts (you're not doing it) but I'm just giving a warning.

U forgot also that its a plugin that is downloaded to minecraft by yourself or someone putted it if u was away.

1.3 and LOWER it is only possible to see him.