The spindly, snake-like Basilisks house hundreds of armor-piercing spines within their upper carapace plates. These spines have been specifically evolved from the defensive urticating hairs of the Slothien and adapted to a new purpose. Basilisks use powerful muscle contractions to launch the spines in volleys at enemies approaching from either the air or the ground.
Due to the Basilisk's evolution of supra-dense chitinous armor, it cannot fire volleys as rapidly as its core strain, however, each spine is covered with a deadly poison, allowing it to kill infantry in seconds. This purpose-specific evolution does have its drawbacks, as it is utterly ineffective to tanks, artillery, and other heavily armored foes. To counter this negativity, the Basilisk must have support from other Zerg strains, such as the ultralisk.
Thanks to the remarkable musculature of a Basilisk (4,000 muscles compared to a terran's 629), the penetrative force delivered by a Basilisk spine is quite astounding. A single spine can easily penetrate 2 cm of solid neosteel even at maximum range. Under any circumstances, massed groups of Basilisks should be approached with extreme caution and preferably siege tank support.