I actually have found a couple on Halo: Combat Evolved (not anniversary). The so called Megg, is one of them. If start over on the Pillar of Autumn, and follow these steps, you can find an M made out of bullet shots, in what appears to be a heart made of blood. First, start the Pillar of Autumn on Legendary mode. Once you get out of the cryo tube, immediately turn around and jump on it. Get to the top of it, turn right, and jump onto the shields machine, and from there to the walkway. Turn and run left to the barrels, jump on to the top one, and wait there for 20 seconds-ish, then jump down, and continue as normal. Get to the captain, skip the cutscene, and go to the checkpoint and out to where the 3 grunts are spawned. Kill them, and continue to the doorway where the assualt rifle lays, pick it up, and return to the bridge. Kill Keyes or one of the crewman, and run back to the door to the bridge, and I think it best to go left to the other doorway, and hide around it until one of the ''INVINCIBLE MARINES'' (AAAHHH RUN IN TERROR!! *Spartan in background swears and shout, "HE WONT DIE!!'', while repeatedly meleeing the man standing in front of him*) comes around the corner. (At this point, make sure you have a full clip of Assault Rifle). Run around the corner, and go beserk, suppressing the marines with AR fire, while running for you life to the door they came in. This may take many tries. It took me atleast 10 tries to make it past them. CUZ DEY WONT DIE!!! Lol. Anways, one you get past them, run quickly into the next room (Notice the door they came out of is open; this will only happen in Legendary). Once in this room, unless standing in front of the hall with marines in it, you can't die, as they cannot enter. Turn right and walk into the next connected room, turn on your flashlight, and look up. Spookily, there will be the M of bullets in the Heart of Human Blood. Creepy. Congrats, you found the Megg. (M of bullets, and Easter Egg? Add it together and get Megg? Lol hence the two G's). I'm proud of myself. I wrote that by myself from memory. Enjoy