The Baron of hell in Doom 64.
The Baron of Hells of Doom 64 are the resurrected carcasses of those from Doom 1, resurrected by the Mother of All Demons. 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.
You thought the Hell Knights were bad? These guys make them look like choir boys. You better have a good supply of ammo and armor to take on this demon.
It's mutations have given it a red-orange colour scheme (rather than greenish which is instead used for the Hell Knight).
The blood in its death sequence is red or green (depending on the NTSC/PAL and Japanese releases, the blood color can be chosen in 2020 rerelease on various systems).
In Doom 64 barons can also injure and infight Hell Knights and vice versa.