Ichthyosaur


 * "I'm sure that beast never swam in terrestrial waters until a week ago!" - Black Mesa Scientist

The Ichthyosaur is one of many alien species encountered in Half-Life that have been teleported to Earth from the borderworld Xen.

Overview
Although it is named after the extinct reptile group, the Ichthyosaurs, it resembles them only in its carnivorous ecology and its general size. When an Ichthyosaur is first encountered in Half-Life, a scientist remarks that while he has been told it originated in the Challenger Deep (in the Pacific Ocean), he is of the opinion that its first taste of a terrestrial ocean was its arrival at the Black Mesa Research Facility.

In Half-Life, Ichthyosaurs are encountered in several water bodies, including a flooded laboratory and in a reservoir behind a hydroelectric dam. They are often placid at first, but quickly become hostile, especially should the player take action against them. The speed and viciousness of the Icthyosaur make the underwater areas of Half-Life some of the most frightening parts of the game.

The Ichthyosaur also makes a single appearance in Half-Life 2. During a teleport malfunction ("harmonic reflux"), Gordon Freeman is momentarily transported outside of City 17, in midair. He looks down, and falls into the ocean. Underwater, he is almost swallowed whole by an Ichthyosaur before being transported elsewhere. Although this encounter is scripted, when an Ichthyosaur is spawned using console commands or a mod such as Garry's Mod it also attacks the player in the same manner, suggesting that the developers planned on Gordon Freeman encountering them more than once.



A Cut Enemy?
Some experiments find that Ichthyosaurs are able to survive on land for limited periods before dying, but also show that they will actually drown if underwater for too long. This latter behaviour may indicate that the creature was not fully implemented in the final game, although equally this may be a design feature as it is what might be expected from an air-breathing organism similar to dolphins, whales and even real ichthyosaurs. The latter interpretation is supported by the frequent surfacing of Icthyosaurs during the game (although this may simply be a ploy by the game designers to attract the player).

Interestingly, most of the sound files associated with the Ichthyosaur contain the prefix "watery death". This is the same prefix used with files and sounds associated with the carnivorous Leech, which suggests that the designers may have originally intended the Ichthyosaur to serve the purpose of the Leech: to appear out of the foggy waters in the ocean, attack the player, and disappear in a similar manner; thus keeping the player out of deep water. Since the "watery death" and the Leeches themselves are included in a large trigger entity in the Valve Hammer Editor, using the Ichthyosaur in this fashion would have made an easy way to keep the player out of water, and may also explain the creature's lack of artificial intelligence. Further supporting this theory is that the Icthyosaur's attack itself spins the player a full 180 degrees, hinting that it would be used as a warning to stay out of the water, lowering the player's health as well as pointing the player to the shore, allowing for an easy  and desired escape. Though it doesn't aggressively attack the player, the Ichthyosaur may suddenly turn or nudge towards the player. It is actually easier to attack the Ichthyosaur, than to be attacked by it. In order to be attacked by an Ichthyosaur, the player must be positioned directly in front of the Ichthyosaur's eyes. The Ichthyosaur attacks when the player is close enough so that he is not able to swim away without receiving damage.

Behind the scenes
According to the book Raising the Bar, it was originally known as "Muddy".