Reckoners

The Reckoners were creatures which appeared in the 2016 apocalyptic horror movie Day of Reckoning.

Overview
The Reckoners have appeared twice in human history, each time during a solar eclipse of the earth. During the first incursion, mankind had no idea what it was dealing with, and it's military forces were all but crippled by overwhelming numbers of relentless Reckoners before they inexplicably chose to return to their lair beneath the earth; not before large portions of civilisation lay in ruins, however.

When the second incursion came, fifteen years later, the deep-mining operation "gates" through which the Reckoners had previously appeared had been capped off with fortified strongholds. Virtually ignoring these measures, the Reckoners again engulfed the world, and the combined armies of man were again faced with a battle they could not win, the sheer weight of numbers of their assailants, and their willingness to fight on when any natural opponent should have died or run, tipping the balance against soldiers who were all too human.

Description
While there are several distinct variants of Reckoner, they share a few common characteristics: they all crawl from deeply-hewn mineshafts; each and every one appear as if they have had their skins flayed to expose tendons, blood and bones; Reckoners are to a fault dedicated to the destruction of humankind; and they are all possessed of a supernatural strength and constitution.

All types of Reckoner are extremely difficult to kill, although enough massed gunfire is usually enough to to put one down. However, they are susceptible to both water and salt, and when one is destroyed, its body will degrade into a misty red mulch.

Origins
Although the Reckoners are subterranean beasts, unearthed by men that sought to drill farther than they ought, there are also exists the possibility that they are demons sent from Hell to cleanse the world of those who are unworthy of Earth's privileges.

Flying
The first type of Reckoner to be encountered, the flying type, looks like a monstrous human with a fanged, Pterosaur-like head and long, clawed wings for in place of arms. These beasts are easily capable of snatching up a human and carrying it off to be devoured elsewhere.

Humanoid
The Humanoid Reckoners are, as their name suggests, long-limbed humanoid creatures with sharp teeth, vicious talons, and a particularly aggressive nature. This type is well adapted for climbing, and are possessed of an astonishing speed.

Spineback
Spinebacks are physically similar to Humanoids but with a fearsome underbite and a forest of razor-sharp spines protruding from their backs. These Reckoners appear to be more group-orientated; most commonly seen as vast herds of flesh-eating pack animals, rather than the hunters that the more specialised of their species appear to be.

Bull
Bull-type Reckoners were the largest of their breed, around the size of an SUV. They were powerfully-built creatures that resembled bulls or perhaps Wildebeest, with a large pair of wickedly curved horns and a thick plate on top of their skulls which could be used as a battering ram.