Final boss - The Doom Wiki at

The final boss (often informally called the Icon of Sin because of the Doom II level of which it is a part) is the final boss of Doom II, in MAP30: Icon of Sin.

Chex Quest - Wikipedia

I just realized this Olivia Pierce : r/Doom

Spider Mastermind, Villains Wiki

Spiderdemon, Doom Wiki

Cyberdemon (Doom 3), Doom Wiki

Doom 3: The Lost Mission, Doom Wiki

The Tower of Doooom - Super Mario Wiki, the Mario encyclopedia

Arch-vile - The Doom Wiki at

Marauder, Doom Wiki

BFG9000 - The Doom Wiki at

Gwyn Lord of Cinder

Boss, Doom Wiki