When the Ichthyosaur is first encountered in the Half-Life chapter Apprehension, a scientist remarks that while he has been told it was hauled from the Challenger Deep in the Pacific Ocean, he is of the opinion that the creature never swam in terrestrial waters until a week before.
In the concept art, the creature is said to use its limbs to pull itself along the murky bottom and to impale and hold prey. An Ichthyosaur has several fins a long, whip-like tail, used for locomotion and two arms that end with a single dagger-like claw. Perhaps the most characteristic feature of this dark green aquatic creature is its large head with an epoccipital bone, and a mouth with sparsely-grown sharp teeth. In Half-Life: Opposing Force, a wall poster depicts the creature's skeleton with the title 'Xenotherus Icthycanthus'.Īlthough it is named after the extinct marine reptile group, the Ichthyosaurs, it resembles them only in its carnivorous ecology and its general size.
