Mountain

Snarling Gorehound

Menace
Whenever another creature you control with power 2 or less enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Conduit Pylons

When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Swamp

Paramecia Coloniex

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
When this creature dies, you may exile it. When you do, put target creature card from your graveyard on top of your library.

Festerleech

Whenever this creature deals combat damage to a player, you mill two cards.
{1}{B}: This creature gets +2/+2 until end of turn. Activate only once each turn.

Faerie Dreamthief

Flying
When this creature enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{2}{B}, Exile this card from your graveyard: You draw a card and you lose 1 life.

Crystal Chimes

{3}, {T}, Sacrifice this artifact: Return all enchantment cards from your graveyard to your hand.

Raucous Theater

({T}: Add {B} or {R}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Stitcher's Supplier

When this creature enters or dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Crow of Dark Tidings

Flying
When this creature enters or dies, mill two cards. (Put the top two cards of your library into your graveyard.)

Desperate Bloodseeker

Lifelink
When this creature enters, target player mills two cards. (They put the top two cards of their library into their graveyard.)

Gnawing Vermin

When this creature enters, target player mills two cards.
When this creature dies, target creature you don't control gets -1/-1 until end of turn.

Unshakable Tail

When this creature enters and at the beginning of your upkeep, surveil 1.
Whenever one or more creature cards are put into your graveyard from your library, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
{2}, Sacrifice a Clue: Return this card from your graveyard to your hand.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Revenge of the Rats

Create a tapped 1/1 black Rat creature token for each creature card in your graveyard.
Flashback {2}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Blazemire Verge

{T}: Add {B}.
{T}: Add {R}. Activate only if you control a Swamp or a Mountain.

Hidden Grotto

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to that card's mana value.