What is "cyberdemon"

The Cyberdemon is a fictional character in the Doom gaming-franchise by id Software, where it was introduced in the first-person shooter game Doom in 1993. Since then, it has appeared in several other id games, including all main-line Doom sequels, Doom RPG, and Wolfenstein RPG as the Harbinger of Doom, along with other related media. The Cyberdemon became one of the most iconic characters of the Doom series along with its protagonist, the " Doomguy", and is often described as one of the most memorable bosses in video gaming history.