Who is Doom Guy?

Context: The Doomguy is a fictional character and the protagonist of the Doom video game franchise of first-person shooters created by id Software. He was created by American video game designer John Romero. He was introduced as the player character in the original 1993 video game Doom. Within the Doom series, Doomguy is a demon hunter space marine dressed in green combat armor who rarely speaks onscreen, and his personality and backstory were intentionally vague to reinforce his role as a player avatar. In Doom Eternal, he is voiced by American voice actor Matthew Waterson, while Jason Kelley voices the character in that game's downloadable content The Ancient Gods: Part Two. He has appeared in several other games developed by id Software, including Quake Champions and Quake III Arena.

Answer: Doom Guy was created by John Romero as the fictional protagonist of the Doom video game. In the game he is a demon hunter space marine dressed in green combat armor.