"Gladiator Beast", known as "Gladial Beast" (剣闘獣グラディアルビースト Guradiaru Bīsuto) in the OCG, is an archetype of cards released in Gladiator's Assault. They resemble futuristic versions of the ancient Roman Colosseum slave-warriors, and consist of many different Attributes and Types, primarily Beast, Beast-Warrior and Winged-Beast. With a few exceptions, all non-Fusion "Gladiator Beasts" have an effect to return to the Deck during the end of a Battle Phase when it battled, and then to Special Summon another "Gladiator Beast" monster to replace it (this is also known as 'tagging out'). The newly Special Summoned "Gladiator Beast" monsters usually gain another effect when Special Summoned in this way.

"Gladiator Beasts" also have four Fusion Monsters, three of which require a specific "Gladiator Beast" monster and either one or two other "Gladiator Beast" monsters as Fusion Material. However, "Polymerization" is not required to Fusion Summon these monsters. Instead, the correct "Gladiator Beast" Fusion Material Monsters are returned to the Main Deck to Special Summon the appropriate "Gladiator Beast" Fusion Monster. This process is otherwise known as Contact Fusion. Several of the "Gladiator Beast" Fusion Monsters are also able to 'tag out' to Special Summon 2 or more "Gladiator Beast" monsters from the Deck.

Nearly every card in the archetype is capable of being returned to the hand, field, or Deck from the Graveyard by utilizing the effects of "Gladiator Beast" monsters or