Forerunner fauna and flora

Land Animals


Halo Dinosaurs are native lifeforms to Halo, possibly exclusive to Installation 04. They are both bipedal and quadruped in stature and somewhat resemble Earth's dinosaurs. The larger animals' names are known as Thorn Beasts and the smaller one has been identified as a Blind Wolf.

Although they did not make it to the final cut of the game, this does not exclude them from Halo as a whole. For example, Engineers didn't make the final cut for Halo: Combat Evolved either, but they were depicted in the Halo Novels. A pack of Brutes ate a Thorn Beast in Halo: Contact Harvest. It's unknown if these animals are meant to be there, or if they are even canon to the plot of Halo: Contact Harvest, but just unseen.

The Dino-Birds
Main Article: Dino-Birds

On the levels Delta Halo, and Regret, there are birds flying around in the sky. They are also in the Halo 3 multiplayer maps Guardian, and Epitaph where they can be examined more closely by using Flycam in Theater or Editor Mode in Forge. At first they seem like dinosaurs, but they are seen in High Charity, so it is also possible that the Covenant brought "food," and they are seen on Installation 05 because they would breed quickly. But then, if they are dinosaurs, the Covenant might bring specimens to their holy city. It may never be known if they are dinosaurs or wildlife brought by the Covenant to use as hunting game. This could be confirmed by the existence of the supply ship complete with a hunting preserve, Infinite Succor from the Halo Graphic Novel. Bungie may very well be the only ones to ever know.

Also, since we know that Halo contains a vast multitude of terrains and environments, much like Earth, it is possible that life has been developing on Halo over the 100,000 years that they have been dormant, such animals like the dino birds. Another reason why animals may NOT be seen is because they have the calcium store necessary for the Flood to infect, so the animals may have been destroyed by the guardians of the construct, and only avian-like animals survive since it was mentioned that Drones do not have sufficient calcium mass to sustain the Flood.

In Halo 2 and Halo 3 these "birds" can be shot and killed; they are difficult to hit and, after being killed, they turn into a splatter of red blood.

It is highly likely that there is no real animal life on the Halo Installations because the Monitors used them as food for the Flood so they could further study them. The birds could be too hard to obtain for the Forerunners and/or their bodies do not contain enough calcium for the Flood to feed off of.

Moths
Main Article: Moths

These moth-like creatures are only seen in the dark Swamps of Alpha Halo. They are one of the first animals seen in Halo: Combat Evolved.

Other
Animal calls were heard in 343 Guilty Spark along with the moths. One of the most common sounds was the sound of an owl hooting. However, there were also some cricket sounds. It is unlikely that these sounds are indeed owls, and crickets.

Sea Worms
Main Article: Sea Worms

Seen on the level Silent Cartographer.

These Sea Worms floated harmlessly on the surface of the water.

Flood Stalk Plants
Seen in: Backwash, 343 Guilty Spark, Gravemind and High Charity.

Forerunner Trees
Forerunner trees are aesthetically similar to modern trees on Earth. They are found on Forerunner Installations and seem to be quite abundant.