Lieutenant Colonel Lewis "Chesty" Puller

Puller is the hard-bitten Marine commander whose reputation precedes him — a legend among the enlisted men before they ever meet him. He drives his officers and troops with blunt, uncompromising discipline, demanding toughness and sacrifice without sentiment, because he expects the fighting ahead to demand exactly that.

William Sadler plays Puller as weathered granite, a man whose authority comes from having already survived what his men are about to face. The show doesn't mythologize him with speeches; it lets his clipped, no-nonsense presence do the work, so his rare moments of visible strain land with real weight.