From Halopedia, the Halo wiki
Thumb birds are a species of native to the colony world of Luyten. They are known to appear in inhabited regions of the planet on a yearly basis, bringing with them plagues and fevers for the human colonists. However, they are hunted by nightgyr lizards, which serve to help stop the spread of the illnesses.
List of appearances
- Halo: Outcasts (First mentioned)
- Halo: Outcasts, chapter 3