On occasion in the late fall and early winter, the Grand Canyon can fill with clouds of fog. This occurs when a layer of warm air traps cold, moist air inside the canyon, creating what’s known as a temperature inversion. The trapped air’s moisture condenses into fog, creating the appearance of a cloud sea lapping at the canyon walls. Such inversions often proceed a big snowstorm, as shown in this video. (Video and image credit: H. Mehmedinovic / SKYGLOWPROJECT; via Gizmodo)
This is a Saiga antelope (Saiga tatarica), a species listed in CITES Appendix II and evaluated as critically endangered by the IUCN Red List. It lives in Asia (Kazakhstan, Mongolia, Russia, Turkmenistan, Uzbekistan).