Hama

Hama were birds' spirits that remained on the material plane instead of going to the afterlife. Usually they could not go to the afterlife for the same reasons as other spirits. It had either not finished the deal that held it to the world, or required revenge. Hama could not speak, but from their songs and croakings one could often guess what they meant. Hama could not talk, even if a mage used the speak with animals spell. Although, Hama could understand any language and dialect. Two of the propagations Hama usually formed were owls or eagles, but they might be other forms of birds. Sparrow, nightingale, parrot, falcon, peacock, and even vulture hama had been seen.They could always be distinguished from living birds, as they always had translucent shells and fiery bright eyes.

Combat
Hama could cause considerable damage with their claws and beak, and could combine these attacks with their wings. Hama felt almost no pain because they were not material beings. Hama, thanks to their ghostliness, could also intimidate many soldiers and travelers. At will Hama could become incorporeal and pass through walls or other barriers. By concentrating, Hama could also fly, but any attack could interrupt this process. Hama were considered lingering spirits rather than undead. (they had no connection to the Negative Material Plane)

Habitat/Society
Hama were usually solitary creatures that performed whatever task tied them to the world, which was usually to fulfill revenge. There were also other reasons. Some people helped Hama to achieve their goals, often to obtain a reward. Priests could be very conductive for Hama by helping them to complete their tasks. Hama could be good scouts or helpers.

Ecology
Once it's task was completed, a Hama went to other planes for it's final reward. Before that, they interacted only with people who could help them complete their task.