Rangmejo

Dino-Birds (tentative name) are a species of flying creature that inhabit numerous former Forerunner worlds. They appear in Halo 2 and Halo 3. The Dino-Birds were first seen on Installation 05 on the level Delta Halo, Regret and Gravemind. 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 ancient terrain "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 (like Earth's rats) by the Forerunners, or, given their pterosaurine nature, an even older civilization.

Trivia

 * In Halo 2 and Halo 3, players can shoot these creatures 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 no visible body parts falling.
 * In a mod of Guardian you can see the eggs of these birds, hinting that maybe Bungie wanted to put these in the game.