Vortigaunt

The Vortigaunts are a race of sapient aliens that originated from an unknown planet. Very long ago, their homeworld was invaded by the Combine, which forced the surviving ones to flee to another world. When the Lambda Incident happened, they took it as a new retreat and invaded Earth.

Feral Vortigaunt
Feral Vortigaunts were slaves that were constantly abused by their Grunt superiors. Because of this, they are unable to be reasoned with and will attempt to kill any enemy on sight. Shazanov had encountered some while attempting to gain control of the facility.