- last post: 01.01.0001 12:00 AM PDT
sigh... Grunts originally came from a Methane-atmosphere planet. so, they evolved to breathe methane. we breathe oxygen. Halo and most human planets also are oxygen-rich.
The thng sticking out of their back is their methane tank, and the thing on their faces is their breathing mask.
Without its mask and tank, the Grunt would suffocate.
And liet pat is right, the colours are that way.