Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) As this artifact enters, choose a creature type. Creatures you control of the chosen type get +2/+2.

Whenever a creature dies, put a charge counter on this enchantment. At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Black creature spells you cast cost {1} less to cast. Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

As this artifact enters, choose a color. Creatures you control of the chosen color get +1/+0. {T}: Add one mana of the chosen color.

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

{T}: Add one mana of any color. {1}, {T}: Untap target legendary creature you control.

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Put any number of target creature cards from your graveyard on top of your library. Draw a card.

Ninjutsu {3}{B}{B} ({3}{B}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever Ink-Eyes deals combat damage to a player, you may put target creature card from that player's graveyard onto the battlefield under your control. {1}{B}: Regenerate Ink-Eyes.

Rat offering (You may cast this spell any time you could cast an instant by sacrificing a Rat and paying the difference in mana costs between this and the sacrificed Rat. Mana cost includes color.) Whenever a permanent is put into an opponent's graveyard, that player loses 1 life.

Skulk (This creature can't be blocked by creatures with greater power.) Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

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

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.

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.

When this creature enters, choose one — • Create a 1/1 black Rat creature token with "This token can't block." • You may sacrifice another creature. If you do, scry 2, then draw a card. • Creatures you control gain menace until end of turn.

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Target player draws two cards and loses 2 life.

As this creature enters, choose a creature type. Whenever a creature of the chosen type dies, you may draw a card.

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

As an additional cost to cast this spell, sacrifice a creature or discard a card. Destroy target creature or planeswalker.

Destroy target nonlegendary creature.

{X}: This creature deals X damage to each creature and each player. Spend only black mana on X.

Target creature gets -1/-1 until end of turn for each Swamp you control.

As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}. Exile target creature or planeswalker.

As an additional cost to cast this spell, sacrifice X creatures. Destroy X target creatures.

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Pestilence Rats's power is equal to the number of other Rats on the battlefield. (For example, as long as there are two other Rats on the battlefield, Pestilence Rats's power and toughness are 2/3.)

When this creature enters, create a number of 1/1 black Rat creature tokens equal to the number of opponents you have. {1}{B}, Sacrifice a creature: Target creature gets -2/-2 until end of turn.

Whenever another nontoken creature dies, you may create a 1/1 black Rat creature token. Rats you control have deathtouch.

Pack Rat's power and toughness are each equal to the number of Rats you control. {2}{B}, Discard a card: Create a token that's a copy of this creature.

Rats you control have menace. {1}{B}, {T}: Create a 1/1 black Rat creature token. {2}{B}{B}, {T}, Sacrifice three Rats: Gain control of target creature.

Starting with you, each player may pay any amount of life. Repeat this process until no one pays life. Each player creates a 1/1 black Rat creature token for each 1 life they paid this way.

Search your library for a card, put that card into your hand, then shuffle.