Doomsday is portrayed as a deadly monster born from the depths of pre-historic Krypton. His creator imbued him with few feelings, mostly hate and destruction which led to him destroying worlds and eventually finding Earth where he meets Superman. The character is best known as Superman's murderer in the 1992 storyline, "The Death of Superman".

Just a simple Head swap, then I detailed his head to match tha classic look of doomsday