Lost soul

The Lost Soul is a flaming, flying skull first introduced in Doom's second episode, The Shores of Hell.

Doom II furthered the use of the Lost Soul by utilizing them as the projectile weapon of the new Pain Elemental monster. The Doom manual gave this description of Lost Souls: "Dumb, tough, flies, on fire, 'nuff said".

Combat characteristics
Arguably one of the most frustrating enemies in the Doom games, Lost Souls float at a leisurely pace until they decide to attack, at which point they launch themselves towards the player at high speed. If they miss, they will continue careening through the air until they hit a wall or other object.

It is uncommon to find a lost soul on its own — they are more often found in groups. The Lost Soul is also the only monster in Doom that does not make any sound when it is alerted, sometimes surprising careless players.

Lost Souls do not leave a corpse; they simply explode. However, there exists a thing type named "Lost Soul Corpse". Despite this it is not possible for an Arch-Vile to resurrect a Lost Soul even if it is crushed as it does not have resurrection frames.

The Lost Soul is the only monster in Doom unaffected by the -respawn switch (including the Nightmare! skill level).

Note that the Lost Soul sprite remains fullbright even in dark areas (this is a property of the monster, not the sprite).

In Doom II (and later in Ultimate Doom), Lost Souls were modified to no longer affect the player's kill score, so it is possible to achieve 100% kills without destroying all Lost Souls on a level. This was undoubtedly due to the addition of the Pain Elemental. Some source ports have reverted to the older score system.

Tactical analysis
The player can stop a lost soul's charge by shooting it while it is attacking. Because of their 100% pain chance, it is often safer to use the pistol, rather than the slower-fire shotgun, so the lost soul won't have enough time to retaliate. Also, Lost Souls will stop when they cross an object in their charge path, ie a shotgun or medkit, stopping them like they would a wall.

Appearance statistics
The IWADs contain the following numbers of Lost Souls:

Doom RPG
In Doom RPG, the Lost Soul appears as a class of monster. There are three variations, identified by color:


 * Phantom (green)
 * Lost Soul (normal colors)
 * Nightmare (blue)

Doom 64
These variations of the Lost Souls do not look much different except that their skulls look more realistic and there is only fire on the top of their skulls.