Overview
Physical Form
The first generation exhibited extreme dimorphism — no two looked alike, because no two Watchers were alike. Some bore vestigial wing-structures, others the bioluminescent skin of their angelic sires. All were enormous by any human standard. 1 Enoch 7 gives their consuming hunger as the defining physical trait: they devoured all human food, then livestock, then humans, then turned on each other. They were appetite given divine scale.
What They Did
1 Enoch 7:2–5 records their trajectory: 'And the women became pregnant and gave birth to great giants whose heights were three hundred cubits. These devoured all the toil of men, until men were unable to sustain them. And the giants turned against men in order to devour them. And they began to sin against birds, and against animals, and against reptiles, and against fish, and they devoured one another's flesh and drank the blood from it.' They were the mechanism by which the Watcher intervention destroyed the pre-Flood world — the direct cause of the Flood's necessity.
Threat Assessment
Beyond their physical scale, the Nephilim Warriors possessed partial celestial inheritance: accelerated healing, strength no weapon could easily overcome, and the gravitational presence of their angelic sires. Their deaths in the Flood did not end them — 1 Enoch 15 states their spirits, released from their hybrid bodies, became the evil spirits that roam the earth. The Flood killed the bodies. The spirits persist.