Creatureless decks contain no creature cards, instead relying on instants, sorceries, artifacts, enchantments, planeswalkers, or lands to control the game and eventually win. That doesn't necessarily mean they'll never control a creature, as noncreature cards can still create creature tokens.
Narset, Parter of Veils can provide card advantage and disruption without adding creatures to the deck, while token-producing spells such as Secure the Wastes still create blockers and threats when needed. Manlands such as Hall of Storm Giants offer another way to close games from the mana base itself.
