Apart from the Xen, Race X and Synth creatures, Antlions or Combine Advisors, the Half-Life and Portal series feature Earth creatures as well. They are either heard, mentioned, or appear as actual NPCs.
Half-Life and its expansions
Birds can be heard outside of Black Mesa. Sound file names suggest they consist of hawks and quails.
Insects can be heard in the exterior maps and some inside maps. Sound file names suggest they consist of flies, bees, and crickets.
The Cockroach (
monster_cockroach) is seen crawling in many places across the Black Mesa Research Facility. His AI was made by Steve Bond. Its health is very low, since walking on it will kill it instantly.
They also appear in Half-Life concept art and early test maps.
The Rat with a Chumtoad in an early test map.
Half-Life 2 and its episodes
With the humans, birds are the only Earth creatures seen during the Combine occupation. No explanation of this particular survival is given in-game. As most NPCs, birds can be killed. Civil Protection officers and Overwatch Snipers can be seen shooting them from time to time, and Xen creatures attack them occasionally as well.
There are three known types of birds in Half-Life 2 and its episodes: the pigeon, the crow and the seagull, although many other types of birds (such as woodpeckers or miscellaneous birds of prey) can be heard in the Outlands. Other unidentified birds (simply named "coast bird" in the sound files) can also be heard along the Coast.
During the teleportation mishap in the Half-Life 2 chapter "A Red Letter Day", Gordon is first sent into the Wasteland, which is filled with crows, one of which gets caught in midair by Lamarr. Immediately afterward, when Gordon temporarily reappears in Kleiner's Lab, it appears that a crow came back with him, as one can be seen at his feet.
In the Half-Life 2 chapter Route Kanal, the player can see a crow quickly take off, only to be eaten by a Barnacle. In the chapter Anticitizen One, an unplugged television on a pile of rubble blocking the doorway leading outside shows an image of the G-Man standing in a wooden boat with a crow on his shoulder. A similar surreal scene can be seen in the WC mappack map "
ickypop", involving the G-Man being held in mid-air by a flying crow.
At White Forest, false alarms are often triggered in the secondary silo by nesting crows.
Although no dove is seen in-game, one is featured on one of the Combine propaganda posters scattered around City 17, above Combine logos, as an ironic symbol of peace. What appears to be a dove is also featured on a beheaded statue seen in Ravenholm's churchyard.
The Fisherman from Lost Coast is very defensive of what remains of Earth's original species. His comments on these species gives the player more knowledge on the effects of Xen lifeforms and the Combine on Earth's natural environment. If the player shoots a seagull, the Fisherman will show he disagrees, saying, in that order and at each seagull killed, "Hey, now! We've lost enough species already!", "What'd that gull ever do to you?", "Don't shoot the gulls! They keep down the leech population!" and finally "Well, suit yourself. I can't stop you.", after which no more seagulls can be seen.
In the Half-Life 2 chapter Highway 17, a seagull can perch on and befoul the Scout Car if Gordon leaves the vehicle unattended for a period of time. The seagull will fly away when the player approaches.
Seagulls flying above St. Olga's beach.
Worms can be seen on the chest of the rotting Citizen corpse model.
Insects can be heard but not seen in the Canals, in the Outlands, and along the Coast. Flies can also often be heard near corpses.
Although not a single cat is seen in Half-Life 2 and its episodes, one is mentioned at the start of Half-Life 2: Kleiner apparently tested his resurrected teleport on a cat, aided by Barney, and the experiment went bad enough to give Barney nightmares about it. When Calhoun learns the teleport is fixed, he replies "You mean it's working? For real this time? Because... I still have nightmares about that cat." Alyx is puzzled and asks several times "What cat?" but does not get an answer. Before being teleported, Alyx asks again "About that cat..." but again is not answered. Later in the game, Barney mistakes a distant Strider roar to a cat meow, saying "Did you hear a cat just now? That damn thing haunts me."
In the Half-Life 2 leak sound files, Barney states "I had to turn the cat right side out again, Gordon, to make sure it was a cat.".
A bronze horse statue can be seen on a column at the end of the chapter "Follow Freeman!", in the map "
d3_c17_13". It was originally featured in WC mappack maps such as "
c17_assault2", as two horses, each on a column, or in the museum in Palace. It can also be found alone on a column in "
d4_streetwar_01", the first street map following Palace. The prefab map "
prefab_government" also contains two horse statues.
During the City 17 uprising, a Citizen says he could "eat a horse, hooves and all".
Half-Life 2 leak texture based on a screenshot of the horse statue on its column, used in the E3 2003 video "Psyche" and the ending sequences of the WC mappack maps "
e3_end" and "
An incomplete rat model can be found in the Half-Life 2 leak files.
Frogs can be heard but not seen in the Canals.
Portal 2 concept art revealed during the PotatoFoolsDay ARG shows Aperture Science producing and growing giant chickens, and that one of them escaped at some point in administration areas.
In Peer Review, the crow appears to have laid three eggs in an old GLaDOS prototype chassis. At the end of the DLC, ATLAS and P-body enter the chassis room on GLaDOS' order, and drive off the bird. GLaDOS then orders them to smash the eggs, but changes her mind in time. Instead, she places them in a small Relaxation Vault-like box, where the chicks are raised with GLaDOS as their new mother. One day, while she is mocking them about their beaks, the one she called "Mr. Chubby Beak" smashes the glass of the vault, making GLaDOS realize that they are actually "little killing machines". She then asks them to go to sleep, telling them that she has got a "big day" for them the next day.
In Test Chamber 09 in Portal 2, GLaDOS teases Chell about her weight. Upon completion of the test, GLaDOS ironically compliments her: "Look at you. Sailing through the air majestically. Like an eagle. Piloting a blimp."
In Portal 2, many insects can be heard in the ruined Enrichment Center. Additionally, some of them can be also found in the Multiverse.
An ant civilization exists on Earth-5912228343.
In a memo by Cave Johnson revealed during the Portal ARG, he states that the "bean counters", a higher authority than himself, told him it was against regulations to practice beekeeping in his office. Johnson ignored this, and his bees' honey won first place in the state finals.
Crickets can be heard outside at the very end of Portal, and are named as such in the captions.
The injection of a praying mantis DNA was the subject of an Experiment made by Aperture Science, eventually leading to creation of Mantis Men. Additionally, mantises are present in 8th and 15th Universe, featured in Perpetual Testing Initiative.
An octopus civilization exists on Earth-5912228342.
Two depictions of jellyfish can be seen in the maintenance areas of Aperture Science Enrichment Center, both drawn with a pencil on a wall. The Nice Little Jellyfish is located in a small office room overlooking Test Chamber 09 while the Big Bad Jellyfish can be found among abandoned offices, near the first Rocket Turret encountered by Chell.
Some mammals can be seen on GLaDOS' screens at the end of Portal. They include cows, a horse, a black bear cub, a rabbit, goats, sheep, and the skull of a cow.
One animal can be chosen among the nine featured in a table at the start of Portal 2’s Calibration Course of the Cooperative Testing Initiative. The table includes 8 mammals, such as a horse, a deer, an elephant, a wolf, a moose, a baboon, a porcupine, and a rhinoceros.
In Portal 2, GLaDOS mentions to Chell and ATLAS and P-body that she sometimes sees deer outside the facility. She then attempts to lure Chell into the "trap" chamber during her escape, telling her a deer can be found there.
A deer is among the 9 animals to be chosen from at the start of Portal 2’s Calibration Course of the Cooperative Testing Initiative.
In Test Shaft 09, Cave Johnson states in one of his pre-recorded messages that the Enrichment Spheres are made out of asbestos to keep out the rats.
A howling wolf can be seen replacing the person on the beach in the mural featured in Chell's room in the Extended Relaxation Center.
A wolf is among the 9 animals to be chosen from at the start of Portal 2’s Calibration Course of the Cooperative Testing Initiative.
Form 21 of the Enrichment Center Test Subject Application Process found on ApertureScience.com contains a list of 1345 items mostly consisting of animals, taken from an index found at the website AnimalPicturesArchives.
List of appearances
- Half-Life: Opposing Force
- Half-Life: Blue Shift
- Half-Life: Decay
- Half-Life 2
- Half-Life 2: Episode One
- Half-Life 2: Episode Two
- Portal 2
- Peer Review
- Perpetual Testing Initiative
- Half-Life: Day One (First appearance)
- Half-Life: Uplink (Non-canonical appearance)
- Half-Life 2: Raising the Bar
- Half-Life 2: Lost Coast (Non-canonical appearance)
- Portal: Still Alive (Non-canonical appearance)
- PotatoFoolsDay ARG
- Randolph the Red-Nosed Turret (Non-canonical appearance)
- Lego Dimensions (Non-canonical appearance)