Mr. Big Cog is a giant cog with a mustache, who appears in both Conker's Bad Fur Day and Conker: Live & Reloaded. He sits next to Carl and doesn't say anything. When Conker returns with all three cogs, they exact revenge by sticking Carl to Mr. Big Cog. He then switches out with Quentin, who really seems to love being stuck there.
In both versions, Mr. Big Cog has slightly different expressions: Prior to "taking care of" The Bullfish, Mr. Big Cog's eyes are wide open. Afterwards, when Carl/Quentin is stuck on Mr. Big Cog's stake center, he is shown to have relaxed his gaze slightly.