Shotgun guy

The Sergeant (sometimes called the Shotgun guy or Shotgun sergeant) is a marine who has been turned into a zombie during the invasion of the UAC bases. He appears as a bald man wearing bloodstained, slate-gray clothing, and wields a shotgun.

The Doom instruction manual says:
 * Same as the Former Humans, but much meaner, and tougher. These walking shotguns provide you with a few extra holes if you're not careful!

In the instruction manual he is referred to as a Former Human Sergeant.

Combat characteristics
The sergeant is armed with a shotgun, which is less powerful than the player's shotgun: one round produces three pellets instead of seven, and each pellet inflicts slightly less damage on average. When the sergeant attacks, he aims his shotgun at the player for about 3/10 of a second and fires a single round. Each pellet has the same dispersal as a trooper's bullet (standard deviation around 9°, to a maximum of ±22°); this is calculated independently for each pellet, so multiple hits are occasionally scored even at very long range. After firing, the sergeant moves again.

When killed, he drops the shotgun, which contains 4 shells (8 on ITYTD and NM). If he subsequently respawns or is resurrected, the shotgun remains. The sergeant's chest explodes as he dies, assuming he is not gibbed.

Tactical analysis
Due to the dispersal of his shotgun pellets, the sergeant is only a marginally greater threat than the trooper at very long range. However, at close range the sergeant can damage the player significantly, and many stock levels create ambushes by placing sergeants on ledges and around corners.

The player's shotgun generally kills individual sergeants at medium and long ranges, and can occasionally kill two or more sergeants with one shot at close range. All other weapons are effective against sergeants, although the pistol leaves him ample time to retaliate, and the fists and chainsaw are dangerous because the player risks being shot at point-blank range.

The sergeant's contribution to monster-monster battles is average at best. He is more durable than a trooper, and can damage more than one creature per shot. However, he fires much less frequently than a player would, and circles his target in an irregular pattern which prevents him from attacking at close range every time. Thus he can be defeated by a healthy Imp or Demon more often than not.

Very large groups of sergeants may suffer significant losses from infighting (as with the red key area in URMEAT.WAD) simply because of the sheer number of pellets being fired.

Certain stock maps (especially those of Knee-Deep in the Dead) include a large number of additional sergeants on UV as compared with the lower skill levels. Their dropped shotguns greatly increase the number of shells available to the player.

Appearance statistics
In classic Doom, the sergeant is first encountered on these maps:

The IWADs contain the following numbers of sergeants:

Doom 3

 * See Shotgun guy (Doom 3).