Nephilim

Nephilim are a race of tall, winged humanoids from the planet of Deneb IV. A very religious people, the Nephilim are the founders of the aptly-named Holy Accord of Deneb.

Physical
At first glance, Nephilim appear similar to tall, slender humans. However their most distinguishing feature is a pair of feathered, avian-style wings attached to their back, which can range in color from white to light brown. Although these wings are large and allow Nephilim to fly with ease, they are capable of folding close enough to their bodies to allow them to potentially pass for humans. In addition, they have a small "tail" of feathers that act as rudders in-flight. Despite their height when compared to humans, Nephilim are nearly half as heavy from hollow bones, more efficient muscles, and internal air sacks.

Seraphim
Despite what the culture on Deneb would lead many to believe, Seraphim (many times simply referred to as "fallen") are simply dark-haired, dark-feathered Nephilim with little genetic differences.