The Gladiator has a large body similar to the sketch of the classic Hell Knight by Adrian Carmack but with the addition of some body armor. However its head resembles a classic Hell Knight but missing one of its eyes, it wields a shield and mace for weapons.
In "The Art of Doom Eternal," it is stated that the Gladiator cannot die, as when his flesh is destroyed, his soul shall wait for his body to rebuild like most demons in folklore, mythology, and in collective religions. But, there is a way to kill him. It involves destroying his shield, which is stated to contain the tormented soul of its master.
It hides behind it's shield and when the eyes of the shield flash green, attack. Do this again and again until you reach his second phase. When the Gladiator's eye flashes, attack. Do it again and prepare for one of the longest glory kills ever.
- The Gladiator's face bears a really strong resemblance to the Baron of Hell from the orginal 1993 Doom, also the Hell Knight from the 1994 Doom 2.