This spell costs {1} less to cast if you control a Wizard. When Academy Journeymage enters the battlefield, return target creature an opponent controls to its owner's hand.

Whenever Ashcoat of the Shadow Swarm attacks or blocks, other Rats you control get +X/+X until end of turn, where X is the number of Rats you control. At the beginning of your end step, you may mill four cards. If you do, return up to two Rat creature cards from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

When Biblioplex Kraken enters the battlefield, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.) Whenever Biblioplex Kraken attacks, you may return another creature you control to its owner's hand. If you do, Biblioplex Kraken can't be blocked this turn.

When Burglar Rat enters the battlefield, each opponent discards a card.

When Campus Guide enters the battlefield, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

When Chittering Rats enters the battlefield, target opponent puts a card from their hand on top of their library.

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

When Elite Instructor enters the battlefield, draw a card, then discard a card.

When Merfolk Pupil enters the battlefield, draw a card, then discard a card. {1}{U}, Exile Merfolk Pupil from your graveyard: Draw a card, then discard a card.

{B}, Sacrifice a creature: Target player discards a card. Activate only as a sorcery.

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

When Ossuary Rats enters the battlefield, it deals X damage to target creature or planeswalker an opponent controls, where X is the number of creature cards in your graveyard.

When Overwhelmed Apprentice enters the battlefield, each opponent mills two cards. Then you scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

{3}{B}{B}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.) As long as Sinuous Vermin is monstrous, it has menace. (It can't be blocked except by two or more creatures.)

{1}{U}, {T}: Draw a card, then discard a card.

This spell costs {2} less to cast if it targets an attacking creature. Put target creature into its owner's library second from the top.

Counter target spell. Draw a card.

({T}: Add {U}.)

({T}: Add {B}.)

Thriving Isle enters the battlefield tapped. As Thriving Isle enters the battlefield, choose a color other than blue. {T}: Add {U} or one mana of the chosen color.

Destroy target creature.