Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Murder

Lord Skitter, Sewer King

Whenever another Rat you control enters, exile up to one target card from an opponent's graveyard.
At the beginning of combat on your turn, create a 1/1 black Rat creature token with "This token can't block."

Zodiac Rat

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Archetype of Finality

Creatures you control have deathtouch.
Creatures your opponents control lose deathtouch and can't have or gain deathtouch.

Brink of Madness

At the beginning of your upkeep, if you have no cards in hand, sacrifice this enchantment and target opponent discards their hand.

Choice of Damnations

Target opponent chooses a number. You may have that player lose that much life. If you don't, that player sacrifices all but that many permanents of their choice.

Rat Colony

This creature gets +1/+0 for each other Rat you control.
A deck can have any number of cards named Rat Colony.

Boon of Emrakul

Enchant creature
Enchanted creature gets +3/-3.

Bad Moon

Deathgrip

The Walls of Ba Sing Se

Defender
Other permanents you control have indestructible.

Bastion of Remembrance

When this enchantment enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Gauntlet of Power

As this artifact enters, choose a color.
Creatures of the chosen color get +1/+1.
Whenever a basic land is tapped for mana of the chosen color, its controller adds an additional one mana of that color.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice this artifact.

Binding Agony

Enchant creature
Whenever enchanted creature is dealt damage, this Aura deals that much damage to that creature's controller.

Gnat Miser

Each opponent's maximum hand size is reduced by one.

Curse of the Restless Dead

Enchant player
Whenever a land enchanted player controls enters, you create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Relentless Rats

This creature gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.

Ruin Rat

Deathtouch
When this creature dies, exile target card from an opponent's graveyard.

Swamp

Locust Miser

Each opponent's maximum hand size is reduced by two.

Karumonix, the Rat King

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Other Rats you control have toxic 1.
When Karumonix enters, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Icon of Ancestry

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Platinum Angel

Flying
You can't lose the game and your opponents can't win the game.

Burglar Rat

When this creature enters, each opponent discards a card.

The Soul Stone

Indestructible
{T}: Add {B}.
{6}{B}, {T}, Exile a creature you control: Harness The Soul Stone. (Once harnessed, its ∞ ability is active.)
∞ — At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: This artifact deals 50 damage to any target.

Attrition

{B}, Sacrifice a creature: Destroy target nonblack creature.

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Crucible of Worlds

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.

Ichor Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When this creature enters, each player gets a poison counter.

Sol Ring

Drainpipe Vermin

When this creature dies, you may pay {B}. If you do, target player discards a card.

The Aetherspark

As long as The Aetherspark is attached to a creature, The Aetherspark can't be attacked and has "Whenever equipped creature deals combat damage during your turn, put that many loyalty counters on The Aetherspark."
+1: Attach The Aetherspark to up to one target creature you control. Put a +1/+1 counter on that creature.
−5: Draw two cards.
−10: Add ten mana of any one color.