

The iconic " status bar face ◊" - a protagonist's concerned face displayed on the bottom that makes amusing grimaces depending on circumstances (getting hit by projectile, picking up a weapon, etc) over the years, it became memetic in Doom fandom and a common source of photoshop memes and shout-outs, as well as being referenced in some of the Id Software's own games.The BFG 9000 is such a memorable weapon that it has an entire article about its influence on gaming culture on Know Your Meme.
DOOM MEMES CODE
The "Get all weapons, ammo, and keys" cheat code IDKFA is very nearly as popular.

The Godmode cheat code IDDQD has become a major piece of modern gaming culture and is regularly referenced in games, jokes, and is crossbred with other related memes such as the Konami Code.The Revenant has become entangled with other skeleton-related memes that circulate the Internet, such as the Agitated Skeleton, the (DOOT) Trumpet Skeleton, and the Spooky Scary Skeletons song.As a result, it quickly became a subject of parody, revolving around similar pieces of Captain Obvious or otherwise unhelpful advice this also extended to "protip" becoming a sarcastic way of invoking such mock assistance. "PROTIP: To defeat the Cyberdemon, shoot at it until it dies." Explanation A fake magazine scan which quickly went viral for the contrast between how convincing it was (with most people not knowing it was fake) and how outrageously unhelpful the "advice" was.
