This is Zog, a native tribal wastelander.
He was big as a boy and hence ended up brutalised and forever shoved to front whenever there is a fight.
Of course, as a native wastelander, he knows that intimidation is usually a better way than actual violence - there's less risk to all involved and even he who backs down gets to fight another day.
Having said that, he'll quite happily shiv you for a pop tart, after all, the wasteland can be a tough place and resources are scarce.