Guff was one of around 60 Unggoy who were assigned to the Jiralhanae-controlled cruiser Rapid Conversion during the First Battle of Harvest. Along with Tukduk, Guff was essentially a toady of Flim's. The three had a rocky relationship with Dadab, Rapid Conversion's Deacon, during their time on the Tiara. During the First Battle of Harvest Tukduk, Guff and Flim were among the last surviving Unggoy when the Tiara was stormed by UNSC forces. During the firefight, Guff was able to wound Colonial Militia recruit Dass before being killed by Staff Sergeant Johnson.