Photos of filming taking place at Saunton Beach in Devon show what certainly looks like the Wild Hunt in a scene from Netflix's adaptation of The Witcher Season 2 (opens in new tab) (via Redanian Intelligence (opens in new tab), who claim to have sources confirming that's who they are).
Players of the videogames will know the Wild Hunt as the final enemies and subtitle of The Witcher 3 (opens in new tab), while readers of the novels will recognize them from their pursuit of Ciri beginning in the fourth book, Time of Contempt. Presumably their role in the series will be different, and this could even be a short cameo appearance setting them up to be antagonists later on.
That bony black armor seems appropriate for the cavalcade of spooky riders who, to avoid spoilers, are described like this in a book found in The Witcher 3: "From farmers and herdsmen, milkmaids to midwives—all the common folk of the Continent whisper, sharing tales of a wraithly procession pounding across the sky. The Wild Hunt, they call it. Winds and gales, storms and blizzards arise when it is sighted, and all grows cold, though the sun shone bright moments before. Some remember only the cold from the shock they encounter, and claim the Riders come always in winter. But nay, this is not so—the Hunt brings its own ice."
Filming of The Witcher was delayed by the COVID-19 pandemic, as well as an injury Henry Cavill suffered (opens in new tab) on set, but the second season is on track for a release later in 2021. We've seen some of the additions to the cast (opens in new tab) already, including the actors portraying Philippa Eilhart, Nenneke, and Dijkstra.