Counterspell

Rooftop Storm

You may pay {0} rather than pay the mana cost for Zombie creature spells you cast.

Endless Ranks of the Dead

At the beginning of your upkeep, create X 2/2 black Zombie creature tokens, where X is half the number of Zombies you control, rounded down.

Geralf, Visionary Stitcher

Zombies you control have flying.
{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Draugr Necromancer

If a nontoken creature an opponent controls would die, exile that card with an ice counter on it instead.
You may cast spells from among cards in exile your opponents own with ice counters on them, and you may spend mana from snow sources as though it were mana of any color to cast those spells.

Lord of the Accursed

Other Zombies you control get +1/+1.
{1}{B}, {T}: All Zombies gain menace until end of turn.

Headless Rider

Whenever Headless Rider or another nontoken Zombie you control dies, create a 2/2 black Zombie creature token.

Zombie Apocalypse

Return all Zombie creature cards from your graveyard to the battlefield tapped, then destroy all Humans.

Diregraf Captain

Deathtouch
Other Zombie creatures you control get +1/+1.
Whenever another Zombie you control dies, target opponent loses 1 life.

Narfi, Betrayer King

Other snow and Zombie creatures you control get +1/+1.
{S}{S}{S}: Return Narfi, Betrayer King from your graveyard to the battlefield tapped. ({S} can be paid with one mana from a snow source.)