Guff

Guff was a Covenant Grunt who served onboard the Rapid Conversion. At the time of the First Battle of Harvest he fought by Flim and Dadab's side on the Tiara station. During a fight, Guff was able to wound Colonial Militia recruit Dass, but before he could finish him off, he was killed by Staff Sergeant Johnson.

Trivia
It's possible that the name Guff may be an attempt at humour. Guff is used colloquially in Britain to describe, amongst other things, breaking wind. This could be a play on the fact that Unngoy breathe methane.