drill instructor

A Drill Instructor is the person in charge of seeing new recruits to the military through boot camp. Almost always holding the rank or rate of a non-commissioned officer, the instructors' duties include imparting discipline and military bearing, ensuring recruits meet basic standards for fitness, marksmanship, and other metrics, and preparing recruits for their next stages of training and combat roles.

The most famous example in media is without question United States Marine Corps Gunnery Sergeant Hartman from the movie Full Metal Jacket, which is also the reasoning behind the naming of this tag, as the term "Drill Instructor" is almost exclusively used by the USMC. Most other services and nationalities use the term "Drill Sergeant" or other variations, but they all are applicable under this tag.