Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of Scute Swarm instead.

Golgari Longlegs

Mind Maggots

When Mind Maggots enters, discard any number of creature cards. For each card discarded this way, put two +1/+1 counters on Mind Maggots.

Dread Summons

Each player mills X cards. For each creature card put into a graveyard this way, you create a tapped 2/2 black Zombie creature token.

Distended Mindbender

Emerge {5}{B}{B} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, target opponent reveals their hand. You choose from it a nonland card with mana value 3 or less and a card with mana value 4 or greater. That player discards those cards.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Corpse Churn

Mill three cards, then you may return a creature card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Nantuko Cultivator

When Nantuko Cultivator enters, you may discard any number of land cards. Put that many +1/+1 counters on Nantuko Cultivator and draw that many cards.

Grapple with the Past

Mill three cards, then you may return a creature or land card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Breach the Multiverse

Each player mills ten cards. For each player, choose a creature or planeswalker card in that player's graveyard. Put those cards onto the battlefield under your control. Then each creature you control becomes a Phyrexian in addition to its other types.

Unseal the Necropolis

Each player mills three cards. Then you return up to two creature cards from your graveyard to your hand. (To mill three cards, a player puts the top three cards of their library into their graveyard.)

Witherbloom Command

Choose two —
• Target player mills three cards, then you return a land card from your graveyard to your hand.
• Destroy target noncreature, nonland permanent with mana value 2 or less.
• Target creature gets -3/-1 until end of turn.
• Target opponent loses 2 life and you gain 2 life.

Krosan Beast

Threshold — Krosan Beast gets +7/+7 as long as seven or more cards are in your graveyard.

Plague Stinger

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Druidic Ritual

You may mill three cards. Then return up to one creature card and up to one land card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Zoological Study

Mill five cards, then return a creature card milled this way to your hand. (Then exile this card. You may cast the artifact later from exile.)

Monster Manual

{1}{G}, {T}: You may put a creature card from your hand onto the battlefield.

Monster Manual // Zoological Study

Grist, the Hunger Tide

As long as Grist, the Hunger Tide isn't on the battlefield, it's a 1/1 Insect creature in addition to its other types.
+1: Create a 1/1 black and green Insect creature token, then mill a card. If an Insect card was milled this way, put a loyalty counter on Grist and repeat this process.
−2: You may sacrifice a creature. When you do, destroy target creature or planeswalker.
−5: Each opponent loses life equal to the number of creature cards in your graveyard.

Scute Mob

At the beginning of your upkeep, if you control five or more lands, put four +1/+1 counters on Scute Mob.

Phyrexian Swarmlord

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
At the beginning of your upkeep, create a 1/1 green Phyrexian Insect creature token with infect for each poison counter your opponents have.

Entropic Decay

Mill four cards. (Then exile this card. You may cast the creature later from exile.)

Gray Slaad

As long as there are four or more creature cards in your graveyard, Gray Slaad has menace and deathtouch.

Gray Slaad // Entropic Decay

Wasteful Harvest

Mill five cards. You may put a permanent card from among the cards milled this way into your hand. (To mill a card, put the top card of your library into your graveyard.)