Cavemen



There is an on the Halo 3 level, Sierra 117, where you can find a family of four monkeys with Marcus Lehto's face. They all vary in size, with the largest holding what appears to be a teddy bear, and the smallest being half the size of said teddy bear.

Guide
To find the monkey family (or apes as some people call them), go past the point where Sergeant Major Avery Johnson says his Pelican was shot down. Then, enter the jungle and stick to the left wall. You will have to climb over some rocks, jump over a giant rock in the way, and then crouch under a tight ledge to find them. You can shoot them but not kill them, although blood will still spurt out, which shows that the respawn cycle is not set up, so they will not die.

Lone Monkey Man
UA2w7riMOC4 There is a monkey man sitting on a cliff outside the level, in the area where you rescue Sergeant Major Johnson. He is accessible by means of a glitch, but he is still visible by using a scoped weapon, such as a sniper or the binoculars. To get where the Caveman is, you must play in at least two players cooperative play. It is much easier to perform with a Gravity Hammer. When you reach him, you can keep running and get out of the level.

Trivia

 * When you shoot any caveman, it will bleed, but if you do anything that would normally kill anything (i.e. grenade or a headshot), nothing will happen, no matter how many times you do this, because they have no death animation. Also, if you shoot the teddy bear, blood will come out.
 * All of the Cavemen are identical in look, but they are all different in size.
 * If viewed with a sniper rifle, there seems to be a stick figure cave drawing drawn by the cavemen in the dark corner behind them.
 * In Halo 3: ODST, a caveman is seen next to Edward Buck in the Epilogue cutscene as an easter egg.
 * Both the Cavemen and Buck and Monkeyman Easter Eggs are mentioned in a Cracked.com article called 7 Creepy Video Game Easter Eggs You'll Wish Were Never Found.