Leeches appear as small, agnathan like creatures that resemble leeches, specifically the terrestrial medicinal leeches. They also resemble lampreys, hagfish, and candirus, and are similar to those animals in ecological niche as well. They are usually white (sometimes pink or yellow) in color.
During the Resonance Cascade, Leeches were teleported to Earth, infesting freshwater and saltwater bodies. They seem to have successful in establishing themselves, to the point that they may have caused the extinction most, if not all, of freshwater and marine fauna. Indeed they are the only creatures commonly seen in water bodies (though in series during the second game, we only mostly see them in the sea), though it is said that some creatures may remain, mostly crabs, though their numbers are said to have been heavily reduced by the leeches. Some Earth creatures remain in inland bodies of water, where insects and frogs can be heard (though it is likely that their numbers have also been heavily reduced by the leeches, much like the crabs). Despite this, statements made by the fisherman say that Earth creatures such as seagulls have turned to hunting them, as it is stated that they keep their numbers down (as there may not be much for the seagulls and other predators of the leeches to eat in the first place due to the leeches themselves). While leeches are commonly seen in freshwater bodies, Ichthyosaurs also seem to occupy freshwater bodies as well, possibly showing non hostile coexistence between Xen fauna.
Half-Life and its expansions
Leeches make their first appearance in Half-Life in some of the flooded sections of the Black Mesa Research Facility after the Resonance Cascade. In addition to being teleported to Earth, they are kept in the Black Mesa Biodome Complex for study. They appear to have six eyes.
In Half-Life 2, they attack Gordon Freeman in a swarm (an attack similar to that of the terrestrial piranha) if he ventures too far into the ocean, to prevent the player from venturing to the "end" of the map and force them to follow the proper path (much like the chopper in the video game Far Cry, for instance). Here the eye count is brought to only two.
Half-Life 2: Lost Coast
In Lost Coast, Leeches behave like in Half-Life 2. Furthermore, the Fisherman reveals that Leeches are used as food. Since ocean fish are now very rare or extinct, the human occupants of coastal areas seem to catch and eat Leeches instead. He also states that their population is kept down by seagulls and that they ate most of the crabs.
Behind the scenes
- In Half-Life, Leeches are minor enemies that do not cause much damage and can be easily killed. In Half-Life 2, they cannot be killed and will drain the player's health in a matter of seconds.
- The Ichthyosaur was originally intended to fulfill the role of keeping the player from venturing too far into the ocean. It can be encountered underwater in "
d2_coast_02", among others, in the playable Half-Life 2 Beta, although it is only heard, not seen, before the player dies.
- In Half-Life 2, if the player uses the console command "notarget" and goes venturing too far in the sea, the Leech will still attack the player. This is because the leeches are not real NPCs, but are rather models.
List of appearances
- Half-Life (First appearance)
- Half-Life: Opposing Force
- Half-Life 2
- Half-Life 2: Lost Coast (Non-canonical appearance)
|Creatures||Alien Aircraft • Alien Controller • Alien Grunt • Armored Headcrab • Barnacle • Boid • Bullsquid • Chumtoad • Fast Headcrab • Gargantua• Gonarch • Headcrab • Houndeye • Ichthyosaur • Leech • Lightning Dog • Nihilanth • Poison Headcrab • Protozoan • Snark • Standard Headcrab • Tentacle • Vortigaunt • Zombie|
|Flora and minerals||Crystal • Fungus • Healing Pool • Light Stalk • Trampoline • Tree|
|Weapons||Black Hole Gun (cut) • Ceiling Turret • Grenade • Hivehand • Sentry Cannon • Snark • Snark Mine|
|Technology||Healing Shower • Thumper|
|Creatures (cut)||Archer • Charger • Fast Walker • Flocking Floater • Kingpin • Mr. Friendly • Panther Eye • Prrobot • Sand Barnacle • Snapbug • Sphere • Stukabat • Unidentified Quiver Creature|