Blue Jackal
From Halopedia, the Halo wiki
"Blue Jackals" can only be seen on one level in Halo 2.
Description
To see a Blue Jackal, you must play the level, Metropolis on any difficulty. Kill a Jackal on the Scarab. If it is on the right place, it will appear blue, as though it were inside the Scarab's tech innards. This is due to coloring error in ground establishment on the Scarab (a part of the Jackal is "inside" the Scarab, and anything labeled as "inside" assumes a blue tinge and dye). It may work with other varieties of Jackal on the same Scarab. Also, if you melee the body, it will change to other colors, strangely including yellow and red. Also, when you turn on your flashlight and point it at the Blue Jackal, it will turn to normal colors, but when you turn off your flashlight, it will revert to blue again. It mostly works if you snipe the Jackals. This occasionaly happens on the level regret. When you hear the marine say "Full car coming up" in the room where you fight the drones, throw a plasma grenade down on the lift before it comes up. when you get to the destination of the tram they will be blue.
This rarely happens to Elites & Grunts (usually Major Grunts).
- This usually happens to the Sniper Jackal that is on board the Scarab.
- This is either a gaming glitch or another easter egg from Bungie, though it's more likely to be a glitch in the game coding.
- It happens most of the time when the game uses moving scenery or BSP so this is most likely the reason.