Spectral Snatcher

Ward—Discard a card. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player discards a card.)
Swampcycling {2} ({2}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Eaten Alive

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

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.)

Merchant of Many Hats

{2}{B}: Return this card from your graveyard to your hand.

Screaming Phantom

Flying
Whenever this creature attacks, mill a card. (Put the top card of your library into your graveyard.)

Zombify

Return target creature card from your graveyard to the battlefield.

Valgavoth, Terror Eater

Flying, lifelink
Ward—Sacrifice three nonland permanents.
If a card you didn't control would be put into an opponent's graveyard from anywhere, exile it instead.
During your turn, you may play cards exiled with Valgavoth. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.

Swamp

Deathcap Marionette

Deathtouch
When this creature enters, you may mill two cards. (You may put the top two cards of your library into your graveyard.)

Valgavoth's Faithful

{3}{B}, Sacrifice this creature: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Fight On!

Return up to two target creature cards from your graveyard to your hand.

Cat-Gator

Lifelink
When this creature enters, it deals damage equal to the number of Swamps you control to any target.

Murder

Summon Undead

You may mill three cards. Then return a creature card from your graveyard to the battlefield. (To mill a card, put the top card of your library into your graveyard.)

Resentful Revelation

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)