Wintherin

The Wintherin are war beasts utilized by both Night Sentinels and Davoth's demon army.

Night Sentinel Wintherin
The Wintherin that are, Huge Beasts that remind us of Dragons in shape but that cannot be guaranteed if they are Legitimately Dragons or a Type of Alien Race that was domesticated for generations, but if it can be accepted that they are Natives of the World of Argent D'Nur, the same World of his Masters, the Night Sentinels, are shown to be white in color with four horns, with a face without visible eyes but vaguely reminiscent of a Skull, have long necks that are very reminiscent of the shape of a Dragon combined with the position of their Wings which are on their back and by having 4 limbs, in his chest are his short but slender arms that are possibly made to attack directly, they have a purplish color fading on their wings and are also in stripes on its body, they have a barb on their tail for an unknown purpose (possibly for melee combat), The last thing that can be said about this Race of Beasts is that they spit out a pale fire of cold colors that differentiates them from their counterpart that they are faithful to Davoth and Hell, which leaves definitively what are Beasts made and tamed for War.

These Creatures are actually very new to the Canon of the Universe of "DOOM", so the information that can be given is more Speculative than confirmed, the closest thing that can be described to something more Acceptable is that, possibly, is that the Wintherins are Natives of the same World of the Night Sentinels, possibly being a heavily used mount in how the final battle looks in "DOOM Eternal: the Ancient Gods Part. 2", so it can already be said that they are Beings who were always a preference for the Night Sentinels.

Demonic Wintherin
The Wintherin used by Davoth's army contrast from the Sentinel variation, they are very similar to their namesakes who are faithful to the Night Sentinels in practically Shape of their Body, their face and even behavior, but with extremely and notable differences: they are dark green in color, they have red instead of purple stripes, they have two glowing red horns and have two barbs on their tail instead of one, as expected, like the Wintherin of the Night Sentinels, they also spit out Fire which should be more intense, more reddish with demonic Colors, these Infernal Beasts are normally seen in the Capital of Demons, Immora.

As had been said, this is more speculation than something confirmed, it could be assumed that this variant of Wintherin are the ones who accompanied the some Night Sentinels who allied themselves with Hell and The purpose of the Khan Maykr