The first Skeleton Knight in Another World light novel written by Ennki Hakari was published by OVERLAP on June 25, 2015, with nine volumes released in Japan.
The official website for the upcoming Skeleton Knight in Another World anime announced today that the series will air in April 2022, and released a brand new trailer and key visual to celebrate the occasion.
Looking like a suit of armor on the outside and a skeleton on the inside, he is the Skeleton Knight.