Rtas 'Vadum's eyes glitch
From Halopedia, the Halo wiki
The Half Jaw's Eyes Glitch only appears in the level The Oracle, right after the level The Arbiter ends.
Summary
The part where you just start and Half Jaw and the other SpecOps Elites turn invisible, look at Half Jaw's eyes. Although he's invisible, his eyes are still green and stand out from his Active Camo. This does not effect him in any way and doesn't occur with any other Elites.
