Rangmejo

These pterosaur-like birds (tentative name) are an unknown species of flying creature that inhabit numerous former Forerunner worlds. They appear in Halo 2 and Halo 3.

The birds were first seen on Installation 05 on the levels Delta Halo and Regret. They appeared again in Halo 3 on the multiplayer maps Guardian and Epitaph. Despite being of presumably alien nature, these creatures bear a surprising similarity to the ancient earth "pterosaur" species.

A double set of wings and a long, rigid tail give them a striking resemblance to Earth's dragonflies as well. It is unknown how they came to populate so many worlds but the fact that their habitats are in areas once inhabited, or at least visited by the Forerunners suggests that they were transplanted either purposely or accidentally by the Forerunners or an even older civilization.

Trivia

 * In Halo 2 and Halo 3, players can shoot these creatures or stick them with Spike Grenades or Plasma Grenades on several Campaign and Multiplayer levels. If you shoot them they will burst and fall to bloody tatters in mid-air, their gory ribbons tend to just "poof" in the air with few visible body parts falling.
 * Upon death, the bird's body disappears for a fraction of a second, then reappears larger than before.
 * The birds seen in High Charity in the Halo 2 level Gravemind are sometimes mistaken for these birds, but upon closer examination, one can see that they are a different species.