The Cacodemons of Doom 64 are resurrected carcasses of those from Doom 1, resurrected by the Mother Demon. They are made from systematically altered dead carnage remade back into corrupted living tissue. The mutations were devastating. The demons have returned stronger and more vicious than before.
They float in the air, belch ball-lightning, and have one horrendously big mouth. If you get too close to one of these monstrosities, you're toast.
It underwent major mutations, becoming beige brown, with a single yellow-green eye, and gaining two arms with broken chains attached, and a rather terrifying face. It resembles Doom II's original Pain Elemental.
Instead of a screech it lets out a loud, frightening hiss when spotting the player, and the body of the monster has animation frames (mostly in the way it swings its arms when in flight), whereas the original Cacodemon floated in a motionless manner.
Fighting the Doom 64 Cacodemon is not dissimilar to dealing with it in earlier games; it retains its capacity for flight, making it able to cross terrain far easier than other demons, though its ball lightning projectiles are somewhat larger and tougher to dodge.
Fast firing weapons like the chaingun, plasma gun and the Unmaker will make short work of the Cacodemon, and it can fall very swiftly to the chainsaw should the player be able to get close enough. The rocket launcher is not ideal if it flies to close to the player, as it also cannot be knocked back with the rockets' concussion blasts, however a Super Shotgun could substitute for this.
Behind the scenes