|Type :||Creature (Human-Angel halfbreed)|
|Notable distinctions :||Silvery angel-like eyes|
|Main weaknesses :||Angel blade|
|Culture(s) of origin :||Abrahamic religions; Hebrew lore|
|Native range :||Earth|
|First appearance :||Clip Show|
Nephilim are presumably created when an angel and a human procreate and conceive a child. Nephilim, for all intents and purposes, physically appear human. Castiel couldn't even tell that a Nephilim he interacted with wasn't human like angels can with other supernatural creatures, until Metatron told him so. However, when a Nephilim is endangered and fighting back, its eyes momentarily flash to a pale, silvery appearance similar to a more dulled version of angels' true eyes.
Besides being undetected to angels' supernatural senses and perception, Nephilim also possess superhuman levels of strength and endurance superior to angels; the one known Nephilim encountered was easily able to physically overpower and throw around two angels in a fight, and shrug off a punch to the face from one of them. Nephilim also have a partial level of supernatural perception, enough to see angels' true forms' halos and tell them apart from humans by it. A Nephilim can be killed by an angel blade.
Human-angel procreation which results in Nephilim has apparently been forbidden amongst angels, who view Nephilim as abominations. According to Metatron, the Nephilim Jane that he and Castiel targeted in 2013 was the only one on Earth.
Metatron and a reluctant Castiel targeted Jane to take her heart as part of the Trials of God to close the gates of Heaven (unbeknownst to Cas, actually as the ingredient for a spell that Metatron would use to expel all angels from Heaven). Though Jane fought back, Castiel successfully killed her with an angel blade. (Clip Show)
The Nephilim are described in the Book of Genesis as the offspring born of the "Sons of God" and "Daughters of Man;" this is generally interpreted to mean that the Nephilim are the children born of fallen angels such as the grigori copulating with human women, and the Nephilim are often regarded as cannibalistic giants. It is also generally believed that the Nephilim were the reason God sent the Great Flood upon the Earth. However, there is much argument and uncertainty and different interpretation of the Nephilim in biblical text.