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.

Icon of Sin (Doom Eternal), Doom Wiki

Speardovich - Super Mario Wiki, the Mario encyclopedia

Samur Maykr, Doom Wiki

The Ultimate Doom - The Doom Wiki at

Icon of Sin (Character) - Giant Bomb

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

Doom (2016 video game) - Wikipedia

A_BrainScream - The Doom Wiki at

Invulnerability Hunter - The Doom Wiki at

Final Doom - Wikipedia

The Gladiator, Doom Wiki

Dark Lord, Doom Wiki

MAP30: Icon of Sin (Doom II), Doom Wiki

Mother Demon, Doom Wiki