Jack o' lantern

From Halopedia, the Halo Wiki

The Jack O' Lantern is an Easter Egg in Halo 2. It is simple to view, as you simply need to destroy a Scorpion, and stand on either the upturned turret or the main body of the Scorpion. Look at the gears on the connecting section, and there is a Jack O' Lantern drawn in blood. It may help to turn on your flashlight.

It is not known what the significance of the Jack O' Lantern is to the creator.

	Easter Eggs
Halo 1 Easter Eggs	.fortune · Birthdate on Tank · Bulletin Board · Hellomyname Keyes · Hugging Elite· Initials on John's Boot · Keyes' Pipe · Megg · Pistol Kanji · Rex · Siege of Madrigal · Talking Grunts · Thirsty Grunt · Three Dead Grunts · Unarmed Marine Easter Egg
Halo 2 Easter Eggs	Bloody UNSC Soldier · Cowardly Grunt · Face in Halo · Face on Gravemind · Finding the Holo-Drone · Flood Blood Symbols · Great Journey Unused Objects · HI BEN · Half-Naked Guy · Halo 2 Skulls · Hidden Cigar · Hidden Gargoyle · Hidden Sniper Rifle · Hippo in Halo · Jack o' lantern · Marathon Symbol from Blind Skull · McDonalds Sign on top of Coagulation · Megg · Messages on Bomb · Notes in Armory · Outskirts Sword · Pound on Keypad · Reversed Messages · Rex · Rooster Teeth · Scarab Gun · Scorpion Pictures · Sid · Siege of Madrigal · Sign in Metropolis · Soccer Ball · Talking Grunts · Type 14 Magnetic/Anti-Tank Mine · Why Am I Here · Zanzibar Eggs
Halo 3 Easter Eggs	Boat on "The Storm" · Carved Letters in Sierra 117 · Cavemen · Easter Egg Towers · Face on the moon · Final Grunt · Flipyap · Halo Music on High Ground · Hidden Blood · Half-Naked Guy · Microsoft Sam · Missing Person Poster · Password-Lacking Marine · Reversed Messages · Rex · Rooster Teeth · Sandbox Warning · Secret Marine on The Covenant · Secret Room On The Ark · Secret Room On The Covenant · Siege of Madrigal · Suicidal Marine · Talking Grunts · Urinating Brute · Valhalla Wall Easter Egg
ODST Easter Eggs	Buck and Monkeyman · Face on Windward · Identification Badge · License Plate Eggs