The Skulk is the primary form of the Kharaa, which all Kharaa players will spawn as from eggs. It is an agile lifeform that uses its razor-sharp teeth to deliver deadly bites and its spike claws to climb on walls and ceilings. Higher Kharaa lifeforms can devolve back to Skulks without using any Personal Resources. Unlike in the original Natural Selection, the skulk no longer gains speed from the Bunnyhop technique used in various Goldsource games. The role of a skill-based movement system has now largely been replaced by the Skulk's new Wall Jumping mechanic to gain speed to more quickly travel across the map and engage in combat.
The Skulk is the most common Kharaa sub-species encountered. Capable of blurring speed and leaps of near limitless height, the Skulk is a light, wiry creature around the size of a large canine. Lacking any significant projectile attacks, it specializes in ambushing its prey in melee range. The Skulk is a quadruped (moves on all fours) – each leg terminates in a long, sharp, bladed bone. Despite having dagger-like leg bones, the Skulk's powerful jaws are its most lethal weapon; if it cannot be stopped before reaching its target, its target has only a slim chance of survival.
Commanders were constantly reporting something "skulking" at the edges of sensor range, or through the shadows, and the name stuck.
- Health: 70
- Armor: 10
- Speed: 7.0
- Gestation Time: 3 seconds
- Alien Vision
- Default Key: F
- Description: Alien Vision grants Kharaa lifeforms enhanced visual sensitivity, allowing them to quickly distinguish Frontiersmen and the terrain even in complete darkness.
- Default Key: Shift (hold)
- Description: The Skulk can crawl silently to ambush unsuspecting prey; stalk reduces move speed and increases grip on wall surface while Wall-Running when in use.
- Description: A passive ability, just like in Natural Selection 1 the Skulk can climb and cling to any surface; crouching will disable wall-running and drop the Skulk to the ground.
- Function: Inflicts damage on a targeted player or structure at melee range.
- Damage: 75
- Damage Type: Normal
- Fire Delay: 0.45
- Energy Cost: 3
- Description: The primary ability of the skulk, using powerful multi-hinged jaws to deal a lot of damage.
- Function: Leaps forward rapidly while on the ground or in the air.
- Energy Cost: 40
- Description: The alternate attack for Skulk, allowing leaps on the ground or midair for a quick attack or escape. Leap becomes available with two completed Hives.
- Function: Tags a targeted player or building with a parasite for position tracking.
- Damage: 10
- Damage Type: Normal
- Fire Delay: 0.5
- Energy Cost: 30
- Description: An instant, long-range attack which infects a targeted Marine or structure with a parasite, allowing all Kharaa players to track the target through Hive Sight and the minimap indefinitely. Parasite is removed upon death of the target, as well as manually removeable for Marines using a Medpack.
- Xenocide (Currently Unavailable)
- Description: The Skulk can rapidly alter its body chemistry to create a devastating explosion, which causes premature death to the creature. Xenocide becomes available with three completed Hives.