Card Trivia:ZXyz: Doom Hydra, the Ultimate King of Terror


 * This is the first "ZXyz" to have no counterpart.


 * This is the only ZXyz so far whose Rank is 0.


 * It's name is fitting for a king, as its effect will protect this card from attacks as long as "ZXyz" or "Number Z" monsters are on your side of the field, hinting that this monster is the ruler of these monsters.