+Rats (29)
: Tap target creature with power 2 or less.
Bog Rats can't be blocked by Walls.
Whenever Carrion Rats attacks or blocks, any player may exile a card from their graveyard. If a player does, Carrion Rats assigns no combat damage this turn.
When Chittering Rats enters the battlefield, target opponent puts a card from their hand on top of their library.
: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.
, : Each creature with mana value X can't attack or block this turn.
When Earsplitting Rats enters the battlefield, each player discards a card.
Discard a card: Regenerate Earsplitting Rats.
Hellbent — As long as you have no cards in hand, Gobhobbler Rats gets +1/+0 and has ": Regenerate Gobhobbler Rats."
At the beginning of combat on your turn, if you both own and control Graf Rats and a creature named Midnight Scavengers, exile them, then meld them into Chittering Host.
Haste
When Hellhole Rats enters the battlefield, target player discards a card. Hellhole Rats deals damage to that player equal to that card's mana value.
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Ichor Rats enters the battlefield, each player gets a poison counter.
Buyback (You may pay an additional as you cast this spell. If you do, put this card into your hand as it resolves.)
Create a 1/1 black Rat creature token.
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.)
Plague Rats's power and toughness are each equal to the number of creatures named Plague Rats on the battlefield.
: Target blocking creature gets -1/-1 until end of turn.
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.)
Exile X target cards from a single graveyard.
: Destroy target artifact, creature, or land you control.
When Ravenous Rats enters the battlefield, target opponent discards a card.
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Relentless Rats gets +1/+1 for each other creature on the battlefield named Relentless Rats.
A deck can have any number of cards named Relentless Rats.
When Rotting Rats enters the battlefield, each player discards a card.
Unearth (: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)
Whenever Septic Rats attacks, if defending player is poisoned, it gets +1/+1 until end of turn.
, Pay 1 life: Sewer Rats gets +1/+0 until end of turn. Activate no more than three times each turn.
Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Stronghold Rats deals combat damage to a player, each player discards a card.
Swarm of Rats's power is equal to the number of Rats you control.
When Thriving Rats enters the battlefield, you get (two energy counters).
Whenever Thriving Rats attacks, you may pay . If you do, put a +1/+1 counter on it.