npc_headcrab_black

Class hierarchy
CBlackHeadcrab ↳CBaseHeadcrab ↳CAI_BaseNPC ↳CBaseCombatCharacter ↳CBaseFlex ↳CBaseAnimatingOverlay ↳CBaseAnimating ↳CBaseEntity
npc_headcrab.cpp

Not to be confused with npc_headcrab_poison (the Half-Life: Alyx entity).

npc_headcrab_black is a point entity available in Half-Life 2, Half-Life 2: Episode One, Half-Life 2: Episode Two, Half-Life 2: Deathmatch, and Black Mesa.

Black headcrabs, also known as poison headcrabs, are a headcrab variant. Upon biting the player, this NPC temporarily reduce the player's health to 1. They are best used in tandem with other melee NPCs like regular headcrabs to make fighting more intense. However, it is risky to group them near NPCs with ranged attacks, as the player will die very easily. In fact, many players are conditioned to kill black headcrabs first because of the threat they pose compared to other enemies.

Commonly found in groups covering a single host poison zombie which hurls its parasite cargo towards the player, they can make a formidable foe so should be placed carefully. Killing the poison zombie will not necessarily kill any of the headcrabs it is carrying, much less all of them (the sole exception may be AR2 secondary fire energy balls). They are also quite resistant to fire and will attack while burning.

Since they are incapable of actually killing the player (only reducing it to 1), they are also often used as a "jumpscare" by themselves to spook the player.

AltNames: This entity is also tied to npc_headcrab_poison.

Note:Some keyvalues, spawnflags, effect flags, inputs, or outputs might not affect an NPC, based on the functionality and coding of the NPC.

Note:In Black Mesa can kill player if the difficulty level is maximum, unlike Half-Life 2.

Bug:No poison screen effect in Black Mesa.

Confirm:Can be fixed with plugins ?

  [todo tested in ?]

Keyvalues

Name (targetname) <string>[ Edit ]

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

BaseHeadcrab:

Start burrowed (startburrowed) <boolean>

Should this npc start burrowed? Will unburrow via input or if an enemy gets near.

Note:If a headcrab is burrowed, it cannot be damaged. Use Kill input if needing to remove such headcrab.

Bug:Black headcrabs lack the animations for un/burrowing (only classic headcrabs have them). Due to the specifics of their AI, they will never unburrow if this keyvalue is used.  [todo tested in ?]

Flags

Start hidden : [65536]

Start hanging from ceiling : [131072]

Inputs

Burrow  !FGD

Burrow. If no burrow points within 512 units, does nothing.

BurrowImmediate  !FGD

Burrow immediate.

Unburrow  !FGD

Unburrow.

StartHangingFromCeiling

Start hanging from ceiling.

DropFromCeiling

Drop if hanging from ceiling.

Outputs

BaseNPC Outputs

OnDamaged Fired when this NPC takes damage (!activator is the damage inflictor). OnDamagedByPlayer Fired when this NPC is hurt by a player (!activator is the attacker or vehicle driver [if friendly fire]). OnDamagedByPlayerSquad Fired when this NPC is hurt by a player OR by one of the player's squadmates (!activator is the attacker or vehicle driver [if friendly fire]). OnDeath Fired when this NPC is killed (!activator is the killer). OnDenyCommanderUse Fired when this NPC has refused to join the player's squad. OnForcedInteractionAborted Fired when the NPC aborts a forced interaction for some reason (target NPC died, couldn't be pathed to, etc.). OnForcedInteractionStarted Fired when the NPC starts a forced interaction. OnForcedInteractionFinished "NPCs in actbusies can no longer perform dynamic interactions." Todo: What does this mean? OnHalfHealth Fired when this NPC reaches half of its maximum health. OnHearCombat Fired when this NPC hears combat sounds. OnHearPlayer Fired when this NPC hears the player. OnHearWorld Fired when this NPC hears a sound (other than combat or the player). OnFoundEnemy <targetname*RedirectOutput/ehandle> Fired when this NPC establishes line of sight to its enemy. OnLostEnemy Fired when this NPC loses its enemy. Usually due to the enemy being killed/removed, or because this NPC has selected a newer, more dangerous enemy. OnLostEnemyLOS Fired when this NPC loses line of sight to its enemy. OnFoundPlayer <targetname*RedirectOutput/ehandle> Fired when this NPC establishes line of sight to its enemy, and that enemy is a player. OnLostPlayer Fired when this NPC loses its enemy, and that enemy was a player. Usually due to the enemy being killed/removed, or because this NPC has selected a newer, more dangerous enemy. OnLostPlayerLOS Fired when this NPC loses line of sight to its enemy, and that enemy is a player. OnSleep Fired when this NPC enters a sleep state. OnWake Fired when this NPC comes out of a sleep state.

Dedicated Console Variables

Cvar/Command	Parameters or default value	Descriptor	Effect
sk_headcrab_poison_health		int	A poison headcrab's spawn health.
sk_headcrab_poison_npc_damage		float	A poison headcrab's damage scale. Doesn't work.

See also

• Npc_headcrab_poison (for Half-Life: Alyx)
• Npc_headcrab
• Npc_headcrab_fast
• Npc_headcrab_runner
• Npc_headcrab_armored
• Category:Headcrabs