Druj is the strongest form of the Mancubi class of demons. They are first encountered in Sector 6 in Doom RPG.

Doom RPG Monsters Zombies Zombie Private Zombie Lieutenant Zombie Captain Commandos Troop Commando Assassin Imps Impling Imp Imp Lord Lost Souls Phantom Lost Soul Nightmare Pinkies Bull Demon Pinky Belphegor Cacodemons Malwrath Cacodemon Wretched Pain Elementals Beholder Rahovart Pain Elemental Revenants Ghoul Fiend Revenant Mancubi Behemoth Mancubus Druj Arch-viles Infernis Arch-vile Apollyon Barons Ogre Hell Knight Baron of Hell Hellhounds Hellhound Cerberus Demon Wolf Bosses Kronos

Doom II RPG Monsters Zombies Zombie Worker Zombie Civilian Zombie Tech Commandos Troop Commando Assassin Imps Impling Imp Imp Lord Lost Souls Phantom Lost Soul Nightmare Pinkies Bull Demon Pinky Belphegor Cacodemons Malwrath Cacodemon Wretched Revenants Ghoul Fiend Revenant Mancubi Behemoth Mancubus Druj Arch-viles Infernis Arch-vile Apollyon Sawcubi Lesser Sawcubus Greater Sawcubus Chainstrosity Watchers Brier Watcher Sentinel Bosses Pinkinator Spider Mastermind VIOS