A gladiator's main purpose was to put on a show for the crowd. And there's no better way to please the crowd than by adding a splash of color to your helmet in the form of Thraex plumes! Well, okay, I guess the crowd would rather see someone loose a limb, but that's much harder to accomplish than adding plumes to your helmet.
The Thraex plumes fit perfectly with the Thraex helmet, but the plumes will also fit in a Minotaur head if you want to create a fabulous minotaur with feather dusters in place of horns. Or use the Thraex plumes as flames for the fire breather!